Fix spurious update cycle attempts

Caused by the fact that external filter lists do not have an
`off` property even when they are not enabled.

Additionally, set the default update cycle check period to 2hr.

src/js/background.js

@@ -50,7 +50,7 @@ const hiddenSettingsDefault = {
     autoCommentFilterTemplate: '{{date}} {{origin}}',
     autoUpdateAssetFetchPeriod: 60,
     autoUpdateDelayAfterLaunch: 105,
-    autoUpdatePeriod: 4,
+    autoUpdatePeriod: 2,
     benchmarkDatasetURL: 'unset',
     blockingProfiles: '11111/#F00 11010/#C0F 11001/#00F 00001',
     cacheStorageAPI: 'unset',

src/js/storage.js

@@ -1481,9 +1481,13 @@ self.addEventListener('hiddenSettingsChanged', ( ) => {
         const now = Date.now();
 
         let needEmergencyUpdate = false;
-        for ( const asset of Object.values(assetDict) ) {
+        for ( const [ assetKey, asset ] of Object.entries(assetDict) ) {
             if ( asset.hasRemoteURL !== true ) { continue; }
-            if ( asset.content === 'filters' && asset.off === true ) { continue; }
+            if ( asset.content === 'filters' ) {
+                if ( µb.selectedFilterLists.includes(assetKey) === false ) {
+                    continue;
+                }
+            }
             if ( asset.obsolete !== true ) { continue; }
             const lastUpdateInDays = (now - asset.writeTime) / 86400000;
             const daysSinceVeryObsolete = lastUpdateInDays - 2 * asset.updateAfter;
@@ -1602,7 +1606,9 @@ self.addEventListener('hiddenSettingsChanged', ( ) => {
             this.loadFilterLists();
         }
         if ( this.userSettings.autoUpdate ) {
-            this.scheduleAssetUpdater(this.hiddenSettings.autoUpdatePeriod * 3600000 || 25200000);
+            this.scheduleAssetUpdater(
+                this.hiddenSettings.autoUpdatePeriod * 3600000 || 25200000
+            );
         } else {
             this.scheduleAssetUpdater(0);
         }