Feature/2611 Notifications on mentions

Riot/Modules/Room/RoomViewController.m

@@ -606,6 +606,10 @@ static CGSize kThreadListBarButtonItemImageSize;
     
     [VoiceMessageMediaServiceProvider.sharedProvider pauseAllServices];
     
+    if([BwiBuildSettings showMentionsInRoom]) {
+        [Mentions setCountMentionsToZeroWithRoomID:self.roomDataSource.roomId];
+    }
+    
     // Stop the loading indicator even if the session is still in progress
     [self stopLoadingUserIndicator];
 }