[ticket/13125] $user->browser to $browser

PHPBB3-13125
Merge pull request #3018 from Senky/ticket/13125

[ticket/13125] Uploaded avatars are not displayed

* Senky/ticket/13125:
  [ticket/13125] $user->browser to $browser
Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/13125] $user->browser to $browser