This reverts commit ae81c85ea4.
Apparently this break way too many things with the installer, such as:
1) makes the resulting ISO not having proper isoconfig and xen.gz installed
2) conflicts with kde packages
I spent some time trying to solve those issues (e.g. using exclude= added
to i686 repos), but without much success. Perhaps somebody with better
understanding of revisor/anaconda could do this one time...