mailu/docs
bors[bot] ba54b77eaf
Merge
2069: Remove Mailu PostgreSQL r=mergify[bot] a=Diman0

## What type of PR?

enhancement

## What does this PR do?
- Removes Mailu PostgreSQ
- Makes roundcube database configurable via setup
- Fixes bug  

As already announced in the release of Mailu 1.8, we will remove Mailu PostgreSQL in 1.9. In PR  we created the necessary documentation to assist migrating to the official PostgreSQL image. This PR completely removes Mailu PostgreSQL. As a bonus I fixed bug . People who were using PostgreSQL with Roundcube are in the situation that Roundcube must keep using SQLite. Roundcube has no migration or export/import functionality to move to a different database flavour (what we do have :). Therefore I have made the roundcube database selection configurable in setup. 

### Related issue(s)
- closes 

## Prerequisites
Before we can consider review and merge, please make sure the following list is done and checked.
If an entry in not applicable, you can check it or remove it from the list.

- [n/a] In case of feature or enhancement: documentation updated accordingly - will happen in Mailu 1.9 release notes.
- [x] Unless it's docs or a minor change: add [changelog](https://mailu.io/master/contributors/workflow.html#changelog) entry file.


Co-authored-by: Dimitri Huisman <diman@huisman.xyz>
..
_templates Restore VERSION_TAG template
assets removing unneeded image
compose Further clarify memory requirements and create newsfragment.
contributors Added new docker repo for test image. Adapted deploy script to use env var for test repo name. Modified travis references to github actions references in docs. Added changelog entry.
kubernetes/mailu simplify
swarm Implement rate-limits
.env Add deploy settings for server
Dockerfile Process code review remarks
antispam.rst Add documentation for the web administration gui.
cli.rst Added documentation for how to switch the database back-end used by Mailu.
conf.py Update documentation config and release notes page.
configuration.rst Merge
database.rst Remove Mailu PostgreSQL. Make roundcube database configurable via setup. Fix .
demo.rst Fixed small typo
dns.rst Update docs/dns.rst
docker-compose.yml Make docker-compose.yml for setup and docs development friendly
faq.rst Add log rotation (if logging to file). Make rsyslog the default.
features.rst remove service status "feature"
general.rst Fix the rst syntax for most documentation
index.rst Add documentation for the web administration gui.
maintain.rst Include a doc section for external certbot
nginx.conf Build the documentation as a Docker image
releases.rst enhanced security changelog entry and added recommendation to recreate secret_key
requirements.txt Added missing extension in conf.py. Added missing library in requirements.txt. Sphinx is only compatible with docutils<0.17
reverse.rst Update reverse proxy documentation (see ).
rpi_build.rst RPi: update doc (alpine version + variables)
setup.rst Preparations for 1.8 release.
webadministration.rst Added documentation for all user statuses.