Prefer CDNs when subscribing to a new list

Also, purging the cache of a list should not remove the
compiled version of that list so that it keep being seen
as cached, but obsolete.

src/js/3p-filters.js

@@ -292,7 +292,7 @@ const renderWidgets = ( ) => {
     dom.cl.toggle('#buttonUpdate', 'active', updating);
     dom.cl.toggle('#buttonUpdate', 'disabled',
         updating === false &&
-        qs$('#lists .listEntry.checked.obsolete:not(.toRemove)') === null
+        qs$('#lists .listEntry.checked.obsolete.cached:not(.toRemove)') === null
     );
     dom.cl.toggle('#buttonPurgeAll', 'disabled',
         updating || qs$('#lists .listEntry.cached:not(.obsolete)') === null
@@ -519,7 +519,6 @@ const onPurgeClicked = ev => {
     //   An external filter list must not be marked as obsolete, they will
     //   always be fetched anyways if there is no cached copy.
     dom.cl.add(liEntry, 'obsolete');
-    dom.cl.remove(liEntry, 'cached');
 
     if ( qs$(liEntry, 'input[type="checkbox"]').checked ) {
         renderWidgets();

src/js/assets.js

@@ -1262,7 +1262,7 @@ async function diffUpdater() {
             } else if ( data.error ) {
                 ubolog(`Diff updater: failed to update ${data.name} using ${data.patchPath}, reason: ${data.error}`);
             } else if ( data.status === 'nopatch-yet' || data.status === 'nodiff' ) {
-                ubolog(`Diff updater: Skip update of ${data.name} using ${data.patchPath}, reason: ${data.status}`);
+                ubolog(`Diff updater: skip update of ${data.name} using ${data.patchPath}, reason: ${data.status}`);
                 assetCacheSetDetails(data.name, {
                     writeTime: data.lastModified || 0
                 });

src/js/messaging.js

@@ -1633,7 +1633,6 @@ const onMessage = function(request, sender, callback) {
     case 'purgeCaches':
         for ( const assetKey of request.assetKeys ) {
             io.purge(assetKey);
-            io.remove(`compiled/${assetKey}`);
         }
         break;