fix: use correct x-forwarded-for header value

root/defaults/nginx/tinyauth-server.conf.sample

@@ -17,6 +17,6 @@ location /tinyauth {
     # Headers needed for authentication
     proxy_set_header X-Original-URL $scheme://$http_host$request_uri;
     proxy_set_header X-Original-Method $request_method;
-    proxy_set_header X-Forwarded-For $remote_addr;
+    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
     proxy_set_header X-Real-IP $remote_addr;
 }