[luau] Login Screen in Red Hat

[W. Wayne Liauh]

That did the trick.  (To play it safe, I manually editted the 
/etc/sysconfig/desktop file.)

But I was really wondering why GDM Configurator didn't work.
Also interestingly, changing the sysconfig/desktop file did not change 
the desktop; it only changed the login screen.  But this is exactly what 
I wanted anyway.