Ignore WaylandEnabled=false if there's no fall back

Hello, there's a potential issue if user decides to uncomment this line in /etc/gdm/custom.conf:

waylandEnabled=false

If Xorg is not available and we disable wayland this way, the user gets stuck after boot. Maybe GNOME should ignore this line if no alternative is present?

Happened to me, I changed a bunch of settings including uncommenting this line while forgetting Xorg is not available in that particular distro.

Thanks for help!