error.html.twig should contain a email value

When getting an exception on env PROD it would be nice to have an email to report to.

Current code has [email] instead of a value.

I'm not sure how to fix this as the email value should come from exception.html.twig

```html
<div id="logs">
    {% include 'TwigBundle:Exception:logs.html.twig' with { 'logs': logger.logs } only %}
</div>
```

Some hints are welcome.