Bugfix: Have the player actually deregister itself from the Keyboard on remove().

src/de/teamteamteam/spacescooter/control/Keyboard.java

@@ -67,7 +67,7 @@ public class Keyboard implements KeyListener {
 	 * Remove the given listener from the event notifications.
 	 */
 	public void removeListener(KeyboardListener listener) {
-		Keyboard.listener.remove(Keyboard.listener);
+		Keyboard.listener.remove(listener);
 	}