Fix menu error. Check dialog tip is added.

addons/escoria-ui-return-monkey-island-dialog-simple/rtmi_dialog_simple.gd

@@ -233,7 +233,8 @@ func show_dialog_tip():
 	pass
 
 func hide_dialop_tip():
-	_dialog_tip.visible = false
+	if _dialog_player.get_children().has(_dialog_tip):
+		_dialog_tip.visible = false
 
 func _on_paused():
 	hide_dialop_tip()