spec file: revert to the previous Release tag
    
    Revert from the current Release tag value `upstream` to the previously used
    `0%{?dist}`, because:
    
    * `0` sorts before `1`, which is usually used as the initial release number
      in downstream packages,
    
    * the information provided by `%{?dist}` is useful, as packages built on
      one OS are not always installable on another OS.
    
    https://fedorahosted.org/freeipa/ticket/6418
    
    Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>