1128831 - Restore python-rhsm-1.8.0.

Bring back python-rhsm-1.8.0 for CentOS users. This is the exact code
that was removed in ecdb3ed0[0].

[0] https://github.com/pulp/pulp/commit/ecdb3ed0d95f2fbaf5f5ec6363ecb3d82386d806

https://bugzilla.redhat.com/show_bug.cgi?id=1128831
I believe python-rhsm is available in Fedora. I don't believe there is a CentOS-like community that rebrands Fedora similar to CentOS and RHEL. If both of those these statements are true then this addition looks right.