Fix get_current_release for new 'ELN' release
    
    The newfangled 'ELN' release broke us here because it has a non-
    integer version; we've never had a Fedora release with a non-
    integer version before. ELN doesn't really "count" for anything
    get_current_release is used for, so we'll just ignore it.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>