Using 0.9 with express 4 causes the app to crash at first request

Hi,

when using Kue 0.9.x with express 4.x.x:

```
var app = require('express')();
var kue = require('kue');

....

app.use(require('basic-auth-connect')(nconf.get('AUTH_USER'), nconf.get('AUTH_PASSWORD')));
app.use(kue.app);
app.listen(nconf.get('PORT'));
console.log('Server listening on port ' + nconf.get('PORT'));
```

The console.log statement is printed correctly but at the first request (both locally and on heroku) it crashes with no error, on node 0.12

No source file or test is named. Reproduce the shown Kue 0.9.x and Express 4.x setup on Node 0.12, then trace the request through app.use(kue.app) after the basic-auth middleware. Done means the first request completes without the application crashing, with a regression test covering the setup if the existing test layout provides a suitable place.

Written by the indexing model from the issue text.