replica-conncheck: improve error message during replicainstall
    
    Replica conncheck may fail for other reasons then network
    misconfiguration. For example, an incorrect admin password might be
    provided. Since conncheck is ran as a separate script in quiet mode,
    no insightful error message can be displayed.
    
    https://fedorahosted.org/freeipa/ticket/6497
    
    Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>