Customer overview page often does not respond in appropriate time

[MarkusKepert]

As a rule of thumb: before reporting an issue

• see if it hasn't been reported (and possibly already been fixed) first
• try with the git master

Describe the bug When logging in and navigating to admin_customers.php?page=customers, the PHP pool went to 100% CPU and the page isn`t loading. Since Version 2.0.21 it runs into HTTP error 503 with browser message and since update to 2.0.23 is shows blank screen. Manually changing adress to index page shows a working froxlor. All other pages of froxlor works fine as well. Trying the request multiple times sometimes lead to working customer page

System information

• Froxlor version: 2.0.23
• Web server: apache2 2.4.38 php-fpm
• DNS server: none
• POP/IMAP Dovecot
• SMTP server: postfix
• FTP server: proftpd
• OS/Version: Debian

To Reproduce Steps to reproduce the behavior:

1. Login (with main admin user, 2FA enabled)
2. Go to Ressources->Customers
3. drink some coffee
4. get new coffee
5. see....nothing

Expected behavior see customer overview page :)

Logfiles PHP error shows AH01071: Got error 'PHP message: PHP Fatal error: Maximum execution time of 60 seconds exceeded in /var/www/html/froxlor/vendor/twig/twig/src/Environment.php on line 766'

[d00p]

Refs #1161 , most likely fixed in https://github.com/Froxlor/Froxlor/commit/41ac71332544169fc17c25493e059931e353b42a (upcoming 2.1.x)