egui_web: Repaint at least every seconds

Just in case the app needs it, e.g. because it has finished a download.

egui_web/src/backend.rs

@@ -200,6 +200,7 @@ pub fn start(app_runner: AppRunner) -> Result<AppRunnerRef, JsValue> {
     let runner_ref = AppRunnerRef(Arc::new(Mutex::new(app_runner)));
     install_canvas_events(&runner_ref)?;
     install_document_events(&runner_ref)?;
+    repaint_every_ms(&runner_ref, 1000)?; // just in case. TODO: make it a parameter
     paint_and_schedule(runner_ref.clone())?;
     Ok(runner_ref)
 }