Fix wall content width

What does this MR do?

A wall post with multiple lines will use the complete available size to display its text.

How confident are you it won't break things if deployed?

Should only change visual aspects.

Links to related issues

How to test

It is hard to test, because this only happens on my mobile phone with increased text size and not with firefox or chrome on my destop.

Screenshots (if applicable)

Before - After

Checklist

• added a test, or explain why one is not needed/possible...
  • only visual change
• no unrelated changes
• asked someone for a code review
• set a "for:" label to indicate who will be affected by this change
• added to the next milestone (see https://gitlab.com/foodsharing-dev/foodsharing/-/milestones, unless it has a "for:Dev" label)
• added an entry to CHANGELOG.md
• added a short text that can be used in the release notes
• Once your MR has been merged, you are responsible to create a testing issue in the Beta Testing forum: https://foodsharing.de/?page=bezirk&bid=734&sub=forum. Please change the MRs label to "state:Beta testing".
  • Consider writing a detailed description in German.
  • Describe in a few sentences, what should be tested from a user perspective.
  • Also mention different settings (e.g. different browsers, roles, ...) how this change can be tested.
  • Be aware, that also non technical people should understand.

Release notes text in German

Ein mehrzeiliger Pinnwandeintrag benutzt jetzt die komplett verfügbare Breite.