Issue on wpforo_bp_format_buddypress_notifications() function

Hi there! Ruben from the GamiPress and AutomatorWP team!

A common user that is using GamiPress, BuddyPress and wpForo together have found that BuddyPress notifications does not get rendered correctly when wpForo is active

The issue comes from the function wpforo_bp_format_buddypress_notifications() (in BuddyPressHooks.php file) which returns an empty string when the action does not matches the wpforo one

The return of this function should be $action instead of an empty string since this causes that any plugin who extends the BuddyPress notifications will get overwritten by this function

Please, release a fix for this as soon as possible