Fix problem of multiple service workers being registered

Source:
https://stackoverflow.com/questions/33816342/how-to-prevent-the-same-service-worker-from-registering-over-multiple-pages

pwa/templates/pwa.html

@@ -36,7 +36,7 @@
     // Initialize the service worker
     if ('serviceWorker' in navigator) {
         navigator.serviceWorker.register('/serviceworker.js', {
-            scope: '.'
+            scope: '/'
         }).then(function (registration) {
             // Registration was successful
             console.log('django-pwa: ServiceWorker registration successful with scope: ', registration.scope);