ENGCOM-1695: [Forwardport] Removed duplicate line and added comment on variable #15561

 - Merge Pull Request #15561 from vgelani/magento2:2.3-develop-PR-port-15362
 - Merged commits:
   1. accf018
   2. f9a86bc

Author: magento-engcom-team

app/code/Magento/Sales/Block/Adminhtml/Order/Create/Totals/Discount.php

@@ -15,9 +15,9 @@
  */
 class Discount extends \Magento\Sales\Block\Adminhtml\Order\Create\Totals\DefaultTotals
 {
-    //protected $_template = 'tax/checkout/subtotal.phtml';
-
-    //protected $_template = 'tax/checkout/subtotal.phtml';
+    /**
+     * @var \Magento\Tax\Model\Config
+     */
     protected $_taxConfig;
 
     /**