Error en el inicio de guión 'app.js nodo messenger-get-started@1.0.0

Mi servidor funciona bien en local, pero cuando comienzo servidor después de dploying a Amazon EC2 que arroja el siguiente error: Esta solución es suficiente para mí aún no ha https://github.com/fbsamples/messenger-platform-samples/issues/43

node dist/app.js

dist nodo / app.js

events.js:141
      throw er; // Unhandled 'error' event
      ^

Error: listen EADDRINUSE :::3979
    at Object.exports._errnoException (util.js:907:11)
    at exports._exceptionWithHostPort (util.js:930:20)
    at Server._listen2 (net.js:1250:14)
    at listen (net.js:1286:10)
    at Server.listen (net.js:1382:5)
    at EventEmitter.listen (/var/www/node_modules/express/lib/application.js:618:24)
    at Object.<anonymous> (/var/www/dist/app.js:120:6)
    at Module._compile (module.js:409:26)
    at Object.Module._extensions..js (module.js:416:10)
    at Module.load (module.js:343:32)

npm ERR! Linux 3.13.0-44-generic
npm ERR! argv /usr/bin/nodejs /usr/bin/npm start
npm ERR! node v4.8.0
npm ERR! npm  v2.15.11
npm ERR! code ELIFECYCLE
npm ERR! mychatapp@1.0.0 start: `node dist/app.js`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the mychatapp@1.0.0 start script 'node dist/app.js'.
npm ERR! This is most likely a problem with the mychatapp package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     node dist/app.js
npm ERR! You can get information on how to open an issue for this project with:
npm ERR!     npm bugs mychatapp
npm ERR! Or if that isn't available, you can get their info via:
npm ERR!
npm ERR!     npm owner ls mychatapp
npm ERR! There is likely additional logging output above.

Ante la sospecha de que no se cargan de process.env, aunque he tratado de codificar los siguientes valores, sino resultado es el mismo.

const VALIDATION_TOKEN = '3f92bb17caf0e11f5632920a402e1687'

const PAGE_ACCESS_TOKEN = 'EAAN9j2KfDg0BAIUrb8ZCaPmgHQXyO88mR55X40gWSJ8gi0CagZC0bJ0wZCETTVFSIUHLC7Fr58O9q8JHrQYFtc1vT2ksjPxV2Z34dqZAUiZCfpyInRa24EyvZABvpK72nooh86TUCVlYn1F9njjIWlDVfvbNw481nZCvOOW0T5EOZAQZDZD'

const SERVER_URL = 'http://http://ec2-54-220-173-191.us-west-