Update TBGVCSIntegration.class.php

TBGContext::getUser()->getID() returned NULL in TBGMailing\_getIssueRelatedUsers (file: TheBugGenie\modules\mailing\classes\TBGMailing.class.php) to fix this TBGContext::setUser has to executed before the comment is saved.

Fixes bug: http://issues.thebuggenie.com/thebuggenie/issues/2059