fixed lazy update of scrolls

gameplay/src/Container.cpp

@@ -1292,6 +1292,7 @@ bool Container::touchEventScroll(Touch::TouchEvent evt, int x, int y, unsigned i
             _scrollingLastTime = gameTime;
             setDirty(DIRTY_BOUNDS);
             setChildrenDirty(DIRTY_BOUNDS, true);
+            updateScroll();
             return false;
         }
         break;