Silence sshd messages during install
    
    Fix for accidentally pushed commit c15ba1f9e8c7d236586d46271fce7c3950b509da
    
    During install we call sshd with no config file, sometimes leading to it
    complaining about missing files or bad config options. Since we're just
    looking for the return code to see if the options are correct, we can
    discard these error messages.
    
    Reviewed-By: Jan Cholasta <jcholast@redhat.com>