Moved katello selinux policy into katello-selinux repository

Hello,

I am moving all Katello plugin related SELinux rules into newly created
repository

https://github.com/Katello/katello-selinux

Note this repository existed before but we have deleted it and created
a new one. If you have a copy, delete and clone again as it was
rewritten from scratch (the original was from the old days when Katello
was not yet a Foreman plugin).

All the rules were moved yesterday, this patch removes those from
Foreman core SELinux policy:

https://github.com/theforeman/foreman-selinux/pull/44

There are no functional changes planned, the only change is the
deployment. If you use Katello make sure katello-selinux package is
installed. We can do this via the installer of SPEC require.

The change will land in the Foreman nightly repo and will be part of
Foreman 1.8 and Katello 2.1 releases.

ยทยทยท -- Later, Lukas #lzap Zapletal