ELN: Wait for 60 * 20 seconds (20 minutes) for packages to sign.
    
    Sometimes the compose is when builds are tagging in the Koji tag
    but are not signed yet. The automation which signs them need some
    time to do so.
    
    In this commit, we wait up to 20 minutes for the signing to happen.
    
    Signed-off-by: Jan Kaluza <jkaluza@redhat.com>