Add remote address to nginx conf

GUIDE.md

@@ -138,6 +138,7 @@ Nginx is a self hosted, highly configurable webserver. Nginx can be configured t
    server {
        listen 80;
        location / {
+           proxy_set_header X-Real-IP $remote_addr;
            proxy_pass http://127.0.0.1:8080;
        }
    }