Fix stale held item appearing when switching worlds (#910)

Signed-off-by: Ayush Thoren <ayushthoren@gmail.com>

Minecraft.Client/ItemInHandRenderer.h

@@ -41,6 +41,7 @@ private:
     int lastSlot;
 public:
 	void tick();
+	void reset();
     void itemPlaced();
     void itemUsed();
 };