fix(cloudopt-adblock): Fix "slice() of undefined" issue

Author: vincentha766

js/cloudopt-adblock.js

@@ -31,7 +31,7 @@ cloudopt.adblock = (function(cloudopt) {
 
         var configuration = {
             filters: [101],
-            whitelist: cloudoptConfig.whitelistAds.slice(),
+            whitelist: cloudoptConfig.whitelistAds? cloudoptConfig.whitelistAds.slice() : [],
             rules: cloudoptConfig.customRule,
             filtersMetadataUrl: 'https://cdn.cloudopt.net/filters/chromium/filters.json',
             filterRulesUrl: 'https://cdn.cloudopt.net/filters/chromium/{filter_id}.txt'