add nullable user property to nextcloud class

[lubiana]

this fixes a deprecation notices on php8.2 which results in an error and therefore inability to register on nextcloud client

ErrorReport:

[24-Apr-2023 19:07:01 UTC] =========== Error ref. 25qisnme ===========

ErrorException: Deprecated: Creation of dynamic property KaraDAV\NextCloud::$user is deprecated in /home/lubiana/dev/private/karadav/lib/KaraDAV/NextCloud.php:33
Stack trace:
#0 /home/lubiana/dev/private/karadav/lib/KaraDAV/NextCloud.php(33): KD2\ErrorManager::errorHandler(8192, '...', '...', 33)
#1 /home/lubiana/dev/private/karadav/lib/KD2/WebDAV/NextCloud.php(380): KaraDAV\NextCloud->auth('...', '...')
#2 /home/lubiana/dev/private/karadav/lib/KD2/WebDAV/NextCloud.php(559): KD2\WebDAV\NextCloud->requireAuth()
#3 /home/lubiana/dev/private/karadav/lib/KD2/WebDAV/NextCloud.php(317): KD2\WebDAV\NextCloud->nc_user('...')
#4 /home/lubiana/dev/private/karadav/lib/KaraDAV/Server.php(44): KD2\WebDAV\NextCloud->route('...')
#5 /home/lubiana/dev/private/karadav/www/_router.php(47): KaraDAV\Server->route('...')
#6 {main}

<errorReport>
{
    "errors": [
        {
            "message": "Deprecated: Creation of dynamic property KaraDAV\\NextCloud::$user is deprecated",
            "errorCode": 0,
            "type": "PHP error",
            "backtrace": [
                {
                    "file": "\/home\/lubiana\/dev\/private\/karadav\/lib\/KaraDAV\/NextCloud.php",
                    "line": 33,
                    "code": {
                        "29": "\t\tif (!$user) {",
                        "30": "\t\t\treturn false;",
                        "31": "\t\t}",
                        "32": "",
                        "33": "\t\t$this->user = $user;",
                        "34": "",
                        "35": "\t\treturn true;",
                        "36": "\t}",
                        "37": ""
                    }
                },
                {
                    "function": "KaraDAV\\NextCloud->auth",
                    "file": "\/home\/lubiana\/dev\/private\/karadav\/lib\/KD2\/WebDAV\/NextCloud.php",
                    "line": 380,
                    "args": {
                        "$login": "string(7) \"lubiana\"",
                        "$password": "string(33) \"redacted\""
                    },
                    "code": {
                        "376": "\t}",
                        "377": "",
                        "378": "\tprotected function requireAuth(): void",
                        "379": "\t{",
                        "380": "\t\tif (!$this->auth($_SERVER['PHP_AUTH_USER'] ?? null, $_SERVER['PHP_AUTH_PW'] ?? null)) {",
                        "381": "\t\t\theader('WWW-Authenticate: Basic realm=\"Please login\"');",
                        "382": "\t\t\tthrow new Exception('Please login to access this resource', 401);",
                        "383": "\t\t}",
                        "384": "\t}"
                    }
                },
                {
                    "function": "KD2\\WebDAV\\NextCloud->requireAuth",
                    "file": "\/home\/lubiana\/dev\/private\/karadav\/lib\/KD2\/WebDAV\/NextCloud.php",
                    "line": 559,
                    "code": {
                        "555": "\t}",
                        "556": "",
                        "557": "\tpublic function nc_user(): array",
                        "558": "\t{",
                        "559": "\t\t$this->requireAuth();",
                        "560": "",
                        "561": "\t\t$quota = $this->getUserQuota();",
                        "562": "\t\t$user = $this->getUserName() ?? 'null';",
                        "563": ""
                    }
                },
                {
                    "function": "KD2\\WebDAV\\NextCloud->nc_user",
                    "file": "\/home\/lubiana\/dev\/private\/karadav\/lib\/KD2\/WebDAV\/NextCloud.php",
                    "line": 317,
                    "args": [
                        "string(21) \"ocs\/v1.php\/cloud\/user\""
                    ],
                    "code": {
                        "313": "\t\t$method = $_SERVER['REQUEST_METHOD'] ?? null;",
                        "314": "\t\t$this->server->log('NC <= %s %s => routed to: %s', $method, $uri, $route);",
                        "315": "",
                        "316": "\t\ttry {",
                        "317": "\t\t\t$v = $this->{'nc_' . $route}($uri);",
                        "318": "\t\t}",
                        "319": "\t\tcatch (Exception $e) {",
                        "320": "\t\t\t$this->server->log('NC => %d - %s', $e->getCode(), $e->getMessage());",
                        "321": "\t\t\thttp_response_code($e->getCode());"
                    }
                },
                {
                    "function": "KD2\\WebDAV\\NextCloud->route",
                    "file": "\/home\/lubiana\/dev\/private\/karadav\/lib\/KaraDAV\/Server.php",
                    "line": 44,
                    "args": {
                        "$uri": "string(21) \"ocs\/v1.php\/cloud\/user\""
                    },
                    "code": {
                        "40": "\t\t}",
                        "41": "",
                        "42": "\t\t$this->nc->setServer($this->dav);",
                        "43": "",
                        "44": "\t\tif ($r = $this->nc->route($uri)) {",
                        "45": "\t\t\t\/\/ NextCloud route already replied something, stop here",
                        "46": "\t\t\treturn true;",
                        "47": "\t\t}",
                        "48": ""
                    }
                },
                {
                    "function": "KaraDAV\\Server->route",
                    "file": "...\/_router.php",
                    "line": 47,
                    "args": {
                        "$uri": "string(22) \"\/ocs\/v1.php\/cloud\/user\""
                    },
                    "code": {
                        "43": "if (isset($_SERVER['REDIRECT_REQUEST_METHOD'])) {",
                        "44": "\t$_SERVER['REQUEST_METHOD'] = $_SERVER['REDIRECT_REQUEST_METHOD'];",
                        "45": "}",
                        "46": "",
                        "47": "if (!$s->route($uri)) {",
                        "48": "\tif (PHP_SAPI == 'cli-server') {",
                        "49": "\t\t$s->dav->log(\"ROUTER: => Route is not managed: 404\");",
                        "50": "\t}",
                        "51": ""
                    }
                }
            ]
        }
    ],
    "context": {
        "date": "2023-04-24T19:07:01+00:00",
        "duration": 155.84897994995117,
        "environment": "development",
        "hostname": "0.0.0.0",
        "http_files": "array(0) {\n}",
        "http_method": "GET",
        "http_post": "array(0) {\n}",
        "http_user_agent": "Mozilla\/5.0 (Linux) mirall\/3.8.1git (Nextcloud, arch-6.2.12-arch1-1 ClientArchitecture: x86_64 OsArchitecture: x86_64)",
        "id": "25qisnme",
        "language": "PHP 8.2.5",
        "memory_peak": 2097152,
        "memory_used": 2097152,
        "os": "Linux",
        "php_sapi": "cli-server",
        "remote_ip": "127.0.0.1",
        "root_directory": "\/home\/lubiana\/dev\/private\/karadav\/www",
        "user_addr": "127.0.0.1",
        "url": "http:\/\/127.0.0.1:8080\/ocs\/v1.php\/cloud\/user?format=json"
    }
}
</errorReport>

[bohwaz]

Great, thank you :)