Change to private function

Change getOptionValueOfGroupSelect to private

Author: edenduong

app/code/Magento/Catalog/Block/Adminhtml/Product/Edit/Tab/Options/Option.php

@@ -380,7 +380,7 @@ public function getOptionValues()
      * @param int $scope
      * @return array
      */
-    public function getOptionValueOfGroupSelect($value, $option, $showPrice, $scope)
+    private function getOptionValueOfGroupSelect($value, $option, $showPrice, $scope)
     {
         $i = 0;
         $itemCount = 0;