When factory settings are loaded Auto-Saving Preferences is disabled.
Currently there is the option to "Skip Auto-Save" which can be toggled,
however based on user feedback from T66675, this is confusing.
It seems that toggling the override for auto-save is too easily confused with the option it's self.
This patch removes the button, replacing it with a note that factory settings are loaded and the user preferences won't be auto-saved.
This is to avoid the case where users load factory settings, then edit them to their liking, expecting auto-save will be used (since it's enabled in the menu).
The method of activating a message box is weak since it doesn't wrap lines, so that part could be improved on, just checking this is a reasonable direction to go since this option caused a lot of confusion.