Commit crimson_penguin patch.

When no connection is established, the server is busy waiting and hogs
the cpu. Force it to sleep at least 1s when all the data have been
sent and received. It may be a bit overkill, let's just wait for
complaints if it is.

src/campaign_server/campaign_server.cpp

@@ -49,6 +49,7 @@ campaign_server::campaign_server(const std::string& cfgfile)
 void campaign_server::run()
 {
 	for(;;) {
+		SDL_Delay(1000);
 		try {
 			network::process_send_queue();