nextcloud: fix reverse proxy

hosts/defiant/services/nginx.nix

@@ -55,6 +55,9 @@
       forceSSL = true;
 
       extraConfig = ''
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+
         server_tokens off;
         gzip on;
         gzip_vary on;