Move the hint message to the callback

Author: dmitriz

examples/socket.io-chat-app/index.js

@@ -15,5 +15,4 @@ const io = require('socket.io')(server);
 // socket-io handlers are in websocket-server.js
 require('./websocket-server.js')(io);
 
-console.log('Listening on localhost:4000');
-server.listen(4000);
+server.listen(4000, () => console.log('Listening on localhost:4000'));