Remove the correct event

Babylon/babylon.scene.ts

@@ -520,7 +520,7 @@
             var eventPrefix = Tools.GetPointerPrefix();
             this._engine.getRenderingCanvas().removeEventListener(eventPrefix + "move", this._onPointerMove);
             this._engine.getRenderingCanvas().removeEventListener(eventPrefix + "down", this._onPointerDown);
-            this._engine.getRenderingCanvas().removeEventListener(eventPrefix + "up",   this._onPointerDown);
+            this._engine.getRenderingCanvas().removeEventListener(eventPrefix + "up",   this._onPointerUp);
 
             Tools.UnregisterTopRootEvents([
                 { name: "keydown", handler: this._onKeyDown },