Fix service worker

@@ -40,7 +40,9 @@
   <script>
     if ('serviceWorker' in navigator) {
       window.addEventListener('load', function () {
-        navigator.serviceWorker.register('/flutter_service_worker.js');
+        navigator.serviceWorker.register('flutter_service_worker.js', {
+        scope: './'
+         });
       });
     }
   </script>