title: socket.error: [Errno 48] Address already in use // python error
body: <p>if I run my flask server on localhost:5000, when I stop it and restart appear some error: socket.error: [Errno 48] Address already in use.
  For to restart the server I must change the port and run (app.run(debug=True, port=65013)). How I can resolve this problem? 
  Thanks</p>