Revert "Revert "Unregister workers""

This reverts commit 6e9db28.

webui/test/cypress/e2e/main.cy.js

@@ -1,3 +1,18 @@
+beforeEach(() => {
+  if (!window.navigator || !navigator.serviceWorker) {
+    return null;
+  }
+  const cypressPromise = new Cypress.Promise((resolve, reject) => {
+    navigator.serviceWorker.getRegistrations().then((registrations) => {
+      if(!registrations.length) resolve();
+      Promise.all(registrations).then(() => {
+        resolve();
+      });
+    });
+  });
+  cy.wrap('Unregister service workers').then(() => cypressPromise)
+});
+
 describe('Frontpage', () => {
     it('renders all elements', () => {
         cy.visit('/');