Big cookie size

Hi,
I would like to understand why the cookie stores the `request.query` since they are not used furder in the code to accomplish the OAuth1 dance.

The cookie is necessary only to compare the `client.temporary(oauth_callback)`'s result

https://github.com/hapijs/bell/blob/9dbf61cf1399e6f46fae0db98c9c0abf31b07a5a/lib/oauth.js#L67-L73

Do you have any insight?

This leads to having a `set-cookie` response header (occasionally) very big and the default NGINX config blocks it.