Remove code only used for RHEL 6.3

Because there are no more EPEL6 repositories on
https://repos.fedorapeople.org/repos/openstack/openstack-juno/
this code can be removed.

Change-Id: Ic8daa0962ad7336f5b9a07c4e44560c860301cc5
Merge "Remove code only used for RHEL 6.3"