Fix global signal owner

examples/compose.rs

@@ -19,7 +19,7 @@ fn app() -> Element {
         }
     });
 
-    let open_compose_window = move |evt: MouseEvent| {
+    let open_compose_window = move |_evt: MouseEvent| {
         let tx = handle.tx();
         dioxus_desktop::window().new_window(
             VirtualDom::new_with_props(compose, Rc::new(move |s| tx.unbounded_send(s).unwrap())),