gesture: Only recognize gestures with as many interacting touches as those handled

If a gesture has denied sequences (so those are presumably handled above/below
the widget), it shouldn't attempt to handle extra touches, even if those end
up matching the expected number of touches.

gtk/gtkgesture.c

@@ -200,6 +200,7 @@ _gtk_gesture_check_recognized (GtkGesture       *gesture,
     _gtk_gesture_set_recognized (gesture, FALSE, sequence);
   else if (!priv->recognized &&
            current_n_points == priv->n_points &&
+           g_hash_table_size (priv->points) == priv->n_points &&
            _gtk_gesture_do_check (gesture))
     _gtk_gesture_set_recognized (gesture, TRUE, sequence);