fix and update service worker

app/service-worker.js

@@ -37,8 +37,11 @@ self.addEventListener('fetch', event => {
 	// don't try to handle e.g. data: URIs
 	if (!url.protocol.startsWith('http')) return;
 
+	// ignore dev server requests
+	if (url.hostname === self.location.hostname && url.port !== self.location.port) return;
+
 	// always serve assets and webpack-generated files from cache
-	if (cached.has(url.pathname)) {
+	if (url.host === self.location.host && cached.has(url.pathname)) {
 		event.respondWith(caches.match(event.request));
 		return;
 	}