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 allows sites using redirect=proxy to still generate ACME
certificates by not passing the acme requests through to the proxy.

We should also consider using this for other features available such as
own error documents, SSI and custom directives.

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>