Deploy as non root user

[andreareginato]

The deploy of mqtt is made as root but it should be as deploy user.
The code that should make this possible is the following one, but it does not work.

app.on('ready', function() {
  debug('MQTT Server listening on port', process.env.NODE_PORT)

  if (process.getuid() === 0)
    require('fs').stat(__filename, function(err, stats) {
      if (err) return console.log(err)
      process.setuid(stats.uid);
    });
});