Website Camera demo broken

I tried the [Camera Demo](https://trackingjs.com/examples/face_camera.html), but it never loaded. I inspected the Console and saw the issue:

```
GET https://trackingjs.com/bower/tracking.js/examples/[object%20MediaStream] 404
```

There's some funny string concatenation going on.

Open the linked Camera Demo and inspect the browser Console and Network requests to trace where the URL containing [object MediaStream] is assembled. Identify the relevant demo entry point from that request, then verify that the camera demo loads without the 404 request.

Written by the indexing model from the issue text.