[ticket/12823] Remove all trailing whitespace

PHPBB3-12823
Merge pull request #2704 from hanakin/ticket/12823

[ticket/12823] Remove all trailing whitespace

* hanakin/ticket/12823:
  [ticket/12823] Remove all trailing whitespace
Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/12823] Remove all trailing whitespace