Create IPA ssh client configuration and move ProxyCommand
    
    The ProxyCommand is non-executable if the user does not have
    a valid shell (like /sbin/nologin) so skip it in that case.
    
    https://pagure.io/freeipa/issue/7676
    
    Signed-off-by: Rob Crittenden <rcritten@redhat.com>
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>