Stale bindings after port change and deploy

I'm running some tests on naught and I've noticed a very strange behaviour: when changing the listening port of express and deploying, connections can still be established on the old port. An actual working connection is not established, but:
- The client hangs until I kill it or stop naught, instead of getting a "Connection Refused" error.
- `netstat -t` shows an established TCP connection on the old port

It seems that naught does not release entirely the binding on the old port after deploying.

The bug can be easily reproduced by cloning https://github.com/shaharke/node-huptime#naught and running the following scenario:
- Start the application: `naught start huptime.js`
- Edit huptime.js: change port = 5000 to port = 5001
- deploy: `naught deploy`
- Run `curl localhost:5000`: the request should hang
- Run `netstat -t` and see that a connection is established on port 5000.