fix getting shop url

Core/CacheWarmer.php

@@ -8,7 +8,7 @@
  * @copyright (c) ProudCommerce | 2020
  * @link          www.proudcommerce.com
  * @package       psCacheWarmer
- * @version       3.1.0
+ * @version       3.1.1
  **/
 
 namespace ProudCommerce\CacheWarmer\Core;
@@ -128,7 +128,7 @@ class CacheWarmer
      */
     protected function _getSitemapUrl()
     {
-        $sSitemapUrl = Registry::getConfig()->getConfigParam('sShopURL');
+        $sSitemapUrl = Registry::getConfig()->getShopURL();
         $sSitemapUrl .= Registry::getConfig()->getShopConfVar('psCacheWarmerSitemapUrl');
 
         return $sSitemapUrl;