- Changed FastCGI buffers for ISPConfig nginx vhost because otherwise you get "upstream sent too big header while reading response header from upstream" on OpenSUSE.
- Added 502 error page ("Bad Gateway").
- Added "fastcgi_intercept_errors on;" to nginx vhost template so that ISPConfig's error pages are displayed instead of the default nginx ones.

- Removed ufw configuration from installer to avoid "PHP Notice:  Undefined index: ufw in /tmp/trunk/install/install.php on line 251".
- Changed phpMyAdmin location in ISPConfig nginx vhost to allow phpmyadmin and phpmyadmin/ (with and without trailing slash).