[ticket/13243] Validate announcement entry for existence in version_helper

PHPBB3-13243
[ticket/13301] Fix called function in apche auth module

PHPBB3-13301
[ticket/13300] Don't show jabber in profile if jabber is disabled

PHPBB3-13300
Merge pull request #3119 from Elsensee/ticket/13243

[ticket/13243] Validate announcement entry for existence in version_helper
Merge pull request #3120 from Elsensee/ticket/13301

[ticket/13301] Fix called function in apche auth module
Merge pull request #3121 from Elsensee/ticket/13300

[ticket/13300] Don't show jabber in profile if jabber is disabled