http1 test Timed out waiting for io.skupper.router.httpListener operStatus down

[kgiusti]

https://github.com/skupperproject/skupper-router/actions/runs/7411520029/job/20166240775#step:34:6251

From looking at the logs it appears that the router has re-connected to the python server immediately after the last test was run but before the listener socket context was closed. This results in a live connection that does not get torn down, which leave the http1 listener in the "active" state.

I think this is a timing issue in the test where the router can re-connect before the python listening socket is closed. Since the router can have only one connection active at a time I think this can be fixed if the test calls listener.shutdown(SHUT_RDWR) immediately after accepting the last server connection to the router. That should prevent a reconnection attempt from the router from succeeding before the listener socket context is closed.