fix path

www/index.html

@@ -55,7 +55,7 @@
       <script src="js/webcam.js"></script>
       <script>
          if ('serviceWorker' in navigator) {
-            navigator.serviceWorker.register('service-worker.js');
+            navigator.serviceWorker.register('js/service-worker.js');
          }
       </script>
    </body>