Can set zero lenght password on constructor 

Patch taken from https://forum.howtoforge.com/threads/monitoring-mysql-mariadb-annoying-aborted-connection-on-var-log-mysql-error-log-hack.89045/

- Updated edit links in html template

This command is using features that are not POSIX-compliant (the [[ and
the || in them), that despite being supported by many shells (including
bash) are not available in dash.

Since system() runs the code with /bin/sh that is an interface defined
as only being POSIX-compliant, with no extensions, it should not presume
a specific shell in that.

Closes: #6326
Signed-off-by: Mattia Rizzolo <mattia@mapreri.org>

Add Debian 11 (Bullseye) to OS detection code in ISPConfig and update config for Debian testing (Sid)