Remove /etc/X11 entry from BSD.root.dist

- FreeBSD hasn't packaged X11 with the distro since 8.x
- X.org hasn't required xorg.conf [in /etc/X11] for some time now
- X.org should work with ${LOCALBASE}/etc/X11
- This path should be included in the X.org package manifest
Until I teach bsd.*.mk to accept NO_ROOT, make this script only accept root users