Fix borrowmut error in nested spawns

packages/fullstack/examples/axum-hello-world/src/main.rs

@@ -48,6 +48,7 @@ async fn get_server_data() -> Result<String, ServerFnError> {
 fn main() {
     #[cfg(feature = "web")]
     tracing_wasm::set_as_global_default();
+
     #[cfg(feature = "ssr")]
     tracing_subscriber::fmt::init();