CI: workaround: wait for dogtag before replica-prepare
    
    In domain level 0 ipa-replica-prepare fails because dogtag is not ready
    so soon after final restart during installation (tests are too fast).
    Wait 30 seconds before ipa-replica-prepare is executed, to make sure
    that dogtag is ready. Remove this workaround when ticket is fixed.
    
    https://fedorahosted.org/freeipa/ticket/6274
    
    Reviewed-By: Martin Babinsky <mbabinsk@redhat.com>