Do better detection on status of CA DS instance when installing.
    
    The conditional used to determine if thd CA 389-ds instance was already
    configured was rather poor so it was possible to pass command-line
    arguments in to confuse it. This would cause it to not be installed at
    all causing the dogtag installation to fail in a strange way.
    
    https://fedorahosted.org/freeipa/ticket/1244