admintool: don't display log file on errors unless logging is setup
    
    The admintool will display the message when something goes wrong:
    
    See %s for more information" % self.log_file_name
    
    This is handy except when finally logging setup is not done
    yet so the log file doesn't actually get written to.
    
    This can happen if validation catches and raises an exception.
    
    Fixes: https://pagure.io/freeipa/issue/7952
    
    Signed-off-by: Rob Crittenden <rcritten@redhat.com>
    Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>