Added comment

RiotShareExtension/ViewController/RoomsListViewController.m

@@ -142,6 +142,9 @@
     [alertController addAction:cancelAction];
     
     UIAlertAction *sendAction = [UIAlertAction actionWithTitle:[NSBundle mxk_localizedStringForKey:@"send"] style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
+        
+        //With the new datasource, we can't get MXRoom instance.
+        
         MXRoom *selectedRoom = [self.dataSource getRoomAtIndexPath:indexPath];
         
         [ShareExtensionManager sharedManager].delegate = self;