[ticket/12540] Fix broken placeholders in language files

PHPBB3-12540
Merge pull request #2454 from nickvergessen/ticket/12540

[ticket/12540] Fix broken placeholders in language files

* nickvergessen/ticket/12540:
  [ticket/12540] Fix broken placeholders in language files
Merge branch 'develop-olympus' into develop-ascraeus

* develop-olympus:
  [ticket/12540] Fix broken placeholders in language files

Conflicts:
	phpBB/language/en/common.php
	phpBB/language/en/posting.php
	phpBB/language/en/ucp.php