PHP Deprecated: Creation of dynamic property XLSXWriter::$tempdir is deprecated in vendor/mk-j/php_xlsxwriter/xlsxwriter.class.php on line 44
PHP Deprecated: htmlspecialchars(): Passing null to parameter #1 ($string) of type string is deprecated in vendor/mk-j/php_xlsxwriter/xlsxwriter.class.php on line 760
These two fixes are required for the library to run without warnings under PHP 8.
PHP 7 is now in end of life status.
Requesting this commit be incorporated in a release of the library.
Fix two deprecated warnings: