[ticket/12694] Remove whitespace at end of line from acp_groups

PHPBB3-12694
Merge pull request #2577 from marc1706/ticket/12694

[ticket/12694] Remove whitespace at end of line from acp_groups
Merge branch 'develop-ascraeus' into develop

# By Marc Alexander
# Via Dhruv Goel (1) and Marc Alexander (1)
* develop-ascraeus:
  [ticket/12694] Remove whitespace at end of line from acp_groups