fix: rollbar template needs PUBLIC_URL defined (#1127)

platform/viewer/public/init-service-worker.js

@@ -10,7 +10,7 @@ var isNotLocalDevelopment =
   ['localhost', '127'].indexOf(location.hostname) === -1;
 
 if (supportsServiceWorker && isNotLocalDevelopment) {
-  const swFileLocation = window.PUBLIC_URL + 'sw.js';
+  const swFileLocation = (window.PUBLIC_URL || '/') + 'sw.js';
   const wb = new Workbox(swFileLocation);
 
   // Add an event listener to detect when the registered