Improve error message on failed Kerberos authentication
    
    When ipa client installation fails due to failed Kerberos authentication,
    make sure that the message about the failed authentication is displayed last.
    This makes it clear to the user that this was the reason for failed
    installation.
    
    https://fedorahosted.org/freeipa/ticket/3573
    
    Reviewed-By: Petr Viktorin <pviktori@redhat.com>