Backport %gpgverify API simplification
    
    Allow EPEL packages to use the simpler %gpgverify API which is available
    in Fedora.  This incorporates the changes made to redhat-rpm-config in
    the following commits:
    
        3490049 (Simplify the API of %gpgverify, 2019-07-25)
        4d93255 (Fix the simple API of %gpgverify, 2019-11-01)