b9c69f5 copr: move epel-6 to rhel+epel from centos+epel

Authored and Committed by praiskup a year ago
    copr: move epel-6 to rhel+epel from centos+epel
    
    Relates to the certificate issues
    https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/thread/KOR3HE2VHHIPDBLDLXTYRMON6JQXCHMW/
    
    The problem was the centos-6 key, not EPEL-6 key.
    
    Reverts: 7b1cf87845c5c595b810fbc3523df96b0e128cd4
    Reverts: 0fc0655e47679ab650070c56fadba3ccb0a7e341