[ticket/12562] Revert "Add max-width to proSilver"

https://tracker.phpbb.com/browse/PHPBB3-12562

PHPBB3-12562
Merge pull request #2648 from dhruvgoel92/ticket/12562

Revert "[ticket/12562] Add max-width to proSilver"

* dhruvgoel92/ticket/12562:
  [ticket/12562] Revert "Add max-width to proSilver"