ending default 404 handler with a newline

I suggest to add a newline after a default 404 handler.

It doesn't matter if you're getting this using a browser, but if you request a page in console, weird thing would happen:

```
alex@server:~/bin$ curl http://localhost:4873/non/existent/page
Cannot GET /non/existent/pagealex@server:~/bin$ 
```

Not a big issue, I'm just tired of seeing this. :)