feat(nginx): use recommended proxy settings

Replaced `proxyWebsockets` with `recommendedProxySettings` for enhanced configurability and alignment with best practices. This improves maintainability and future compatibility of the nginx configuration.

systems/x86_64-linux/sgx/nginx.nix

@@ -36,7 +36,7 @@
         forceSSL = true;
         locations."/" = {
           proxyPass = "http://127.0.0.1:8384";
-          proxyWebsockets = true;
+          recommendedProxySettings = true;
         };
       };
     };