You can also add a uwsgi_param to your location to force uwsgi to see the connection as https.

Here's what part of my nginx config looks like, UWSGI_SCHEME is the param that needs set.

        location / {

                include        uwsgi_params;
                root   /opt/www/managesite/htdocs;
                uwsgi_param UWSGI_SCHEME https;
                uwsgi_pass 127.0.0.1:3031;
        }