This reverts merge request !841

- sourced out duplicate code

Add description text for logging options.

Optimized prosody configuration for full conversations.im feature compartibility including full OMEMO support

Fixed#5019 LE cert problem in mirror setups. This patch disables the creation of Let's encrypt SSL certs on mirrored slave servers.

- Fixed #5027 add support for PHP 7.1 and 7.2 on nginx servers in apps vhost.
- suppress some warnings in simplepie.inc.php

global option to enable pagespeed with nginx - allows to enable pagespeed even if no webserver-config is selected

- fixed backups not downloadable on multiserver slave, fixes #4973

- fixed accidently deleting mysql r/o user completely when it is removed from a single database, fixes #4963

Fix bug where in a multiserver setup, deleting a backup will not remove its details from the master database as well.

Fix typo in parent user related variable when creating new jailkit shell user. This bug was interfering with the correct functioning of the plugin.

+ fix php-fpm chroot