Merge #1071

1071: Update rainloop to 1.13.0 r=mergify[bot] a=hoellen

## What type of PR?
enhancement

## What does this PR do?
This updates Rainloop to the version 1.13.0

## 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.


Co-authored-by: hoellen <dev@hoellen.eu>

towncrier/newsfragments/1071.feature

@@ -0,0 +1 @@
+Update Rainloop to 1.13.0

webmails/rainloop/Dockerfile

@@ -5,7 +5,7 @@ RUN apt-get update && apt-get install -y \
   && rm -rf /var/lib/apt/lists \
   && echo "ServerSignature Off" >> /etc/apache2/apache2.conf
 
-ENV RAINLOOP_URL https://github.com/RainLoop/rainloop-webmail/releases/download/v1.12.1/rainloop-community-1.12.1.zip
+ENV RAINLOOP_URL https://github.com/RainLoop/rainloop-webmail/releases/download/v1.13.0/rainloop-community-1.13.0.zip
 
 RUN apt-get update && apt-get install -y \
       unzip python3-jinja2 \