delete interaction menu effect when menu is closed

This prevents a lot of effects without command target from floating around.

planet/Objects.ocd/HUD.ocd/ObjectInteractionMenu.ocd/Script.c

@@ -100,6 +100,9 @@ func Destruction()
 	var i = ContentsCount(), obj = nil;
 	while (obj = Contents(--i))
 		obj->RemoveObject(false);
+	// Remove check objects effect.
+	if (cursor)
+		RemoveEffect("IntCheckObjects", cursor);
 }
 
 // used as a static function