Log to fd behind an lemonldap::ng portal show debug log instead of main page

Description

Wen we log to fd behind an lemonldap::ng portal we get the debug log instead of main page

Distribution Name and Version

Debian 8.9

FusionDirectory Version

1.2-fixes

PHP version used

PHP 5.6

Origin of php packages

Debian

Steps to Reproduce

1. go to FusionDirectory
2. log
3. get a debug log on the page instead of the main menu

Expected behavior:

Getting the main page

Actual behavior:

I'am getting a white page with debug log on it and i need to add main.php to the url to get the main page

Reproduces how often:

100% time when debug is activated

Additional Information

none