Modifying the config.ini as a1s suggests works fine, but is there any reason to prefer a hardcoded 'localhost' over socket.getfqdn()? We're already listening on all interfaces, we might as well be using a useful name. That way the user doesn't have to be bothered with starting the demo, stopping it, reconfiguring it, and then restarting it.

I have a trivial patch ready to make this change if dropping localhost is okay.