All you need to do is:

• setup SSL support in Tomcat - excellent guide can be found here: http://java.dzone.com/articles/setting-ssl-tomcat-5-minutes
• change Javascript config property serverUrl to use wss protocol and secure port, e.g. 

var config = {

  serverUrl: "wss://localhost:8443/websocket",

  OnOpen: function (event) { },

  OnClose: function (event) { }

};

If you are using not trusted certificate, remember to also update your webapp to use secure connection (otherwise user wont be able to accept not trusted connection in browser)