Only cache stuff from maps.netsyms.net in serviceworker

www/settings.js

@@ -5,7 +5,7 @@
  */
 
 var SETTINGS = {
-    cacheversion: "v1.4.0_4",
+    cacheversion: "v1.4.0_5",
     maptileurls: {
         liberty: {
             url: "https://maps.netsyms.net/styles/osm-liberty/{z}/{x}/{y}.png",

www/sw.js

@@ -4,7 +4,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-var cachename = "v1.4.0_4";
+var cachename = "v1.4.0_5";
 
 self.addEventListener('fetch', (event) => {
     event.respondWith(
@@ -12,7 +12,10 @@ self.addEventListener('fetch', (event) => {
         return resp || fetch(event.request).then((response) => {
             return caches.open(cachename).then((cache) => {
                 try {
-                    cache.put(event.request, response.clone());
+                    // only cache map data
+                    if (event.request.url.includes("maps.netsyms.net")) {
+                        cache.put(event.request, response.clone());
+                    }
                 } catch (ex) {
 
                 }