Remove http to https redirect in nginx container

[ffont]

Our Docker setup includes an Nginx container which routes requests to the Django application via Gunicorn. Requests made over http are redirected to the https version. Our intention is to only allow https and this is why we added this redirect. However the redirect is probably not a good idea as it could happen in some situations that after the http request with sensible data (such as access tokens) the client is transparently redirected to https without even noticing. That would mean that http requests would still be made.

We need to handle http requests in a better way, most probably returning an error if the request is made inside the domain of the API, and allowing the redirect if the request is performed in the web frontend.

[ffont]

Production site configuration has also been updated to return error if accessing the api using non-https connection.