copr: login as "fedora" user instead of root
    
    Otherwise we get following error
    
        Please login as the user "fedora" rather than the user "root".
    
    Which messes up our variables - `$fedora` contains the `Please login
    as the user "fedora" rather than the user "root".` warning and
    therefore `new_volume_name` is
    
        copr-builder-x86_64-fPlease login as the user "fedora" rather than the user "root".-20201101_155103