bug fixed: when hosting several SoundRTS servers on the same machine (using several ports with the -p command-line option), each registering server would unregister the other servers with the same IP address even if the port number is different

Note: a very minor bug is left unfixed because it would require to fix the old versions: when a server is closed and unregisters itself, it will unregister the other servers on the same machine too; but the other servers will reappear at the next periodic registering.