Test the upstream fix for repeating banner messages issue from upstream.

We’ve observed that when connecting via sshpiper, if the user is in a deny group, the banner message is displayed repeatedly even if the connection was closed by the upstream server.

This differs from a direct ssh connection to the server, where the banner is shown only once and the connection is closed immediately.

Refer to the issue https://github.com/tg123/sshpiper/issues/593 for more details.

The author provided a fix for it upstream - https://github.com/tg123/sshpiper/pull/594. We need to test if it is acceptable to us in staging