1649: Update docs/reverse.rst with Traefik v2+ info r=mergify[bot] a=patryk-tech
## What type of PR?
Documentation
## What does this PR do?
Adds information about using Traefik v2+ as a reverse proxy.
### Related issue(s)
Closes#1503
## Prerequistes
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.
- [x] In case of feature or enhancement: documentation updated accordingly
- [x] Unless it's docs or a minor change: add [changelog](https://mailu.io/master/contributors/guide.html#changelog) entry file.
1673: Remove rspamd unused env var from start script r=mergify[bot] a=cbachert
## What type of PR?
Cleanup
## What does this PR do?
Remove unused environment variable FRONT_ADDRESS in rspamd. FRONT_ADDRESS references were removed with commit 8172f3e in PR #727 like mentioned in chat https://matrix.to/#/!MINuyJjJSrfowljYCK:tedomum.net/$160401946364NGNmI:imninja.net?via=huisman.xyz&via=matrix.org&via=imninja.net
```
Mailu$ grep -r "FRONT_ADDRESS" core/rspamd/
core/rspamd/start.py:os.environ["FRONT_ADDRESS"] = system.get_host_address_from_environment("FRONT", "front")
```
### Related issue(s)
N/A
## Prerequistes
- [x] Documentation updated accordingly: No documentation to update
- [x] Add to changelog: Minor change
Co-authored-by: Patryk Tech <git@patryk.tech>
Co-authored-by: cbachert <cbachert@users.noreply.github.com>
