bug/#1040 - explicit call to invalidate after animation

Thank you @InI4 for this bug fix suggestion.

Impacted classes:
* `MapController`: added an explicit call to `invalidate` after animation, in method `onAnimationEnd`

osmdroid-android/src/main/java/org/osmdroid/views/MapController.java

@@ -431,6 +431,7 @@ protected void onAnimationEnd() {
             mZoomOutAnimationOld.reset();
             setZoom(mTargetZoomLevel);
         }
+        mMapView.invalidate();
     }
 
     @TargetApi(Build.VERSION_CODES.HONEYCOMB)