Luanti rename: builtin (#15324)

builtin/mainmenu/settings/dlg_settings.lua

@@ -1,4 +1,4 @@
---Minetest
+--Luanti
 --Copyright (C) 2022 rubenwardy
 --
 --This program is free software; you can redistribute it and/or modify
@@ -743,7 +743,7 @@ end
 
 local function eventhandler(event)
 	if event == "DialogShow" then
-		-- Don't show the "MINETEST" header behind the dialog.
+		-- Don't show the header image behind the dialog.
 		mm_game_theme.set_engine(true)
 		return true
 	end