Update app/code/Magento/Sales/Model/Order/Creditmemo/Total/Discount.php

Co-Authored-By: Rus0 <andonid88@gmail.com>

Author: Oleksii Korshenko

app/code/Magento/Sales/Model/Order/Creditmemo/Total/Discount.php

@@ -32,7 +32,7 @@ public function collect(\Magento\Sales\Model\Order\Creditmemo $creditmemo)
          * If credit memo's shipping amount is set and Order's shipping amount is 0,
          * throw exception with different message
          */
-        if ( $baseShippingAmount && $order->getBaseShippingAmount() <= 0 ) {
+        if ($baseShippingAmount && $order->getBaseShippingAmount() <= 0) {
             throw new \Magento\Framework\Exception\LocalizedException(
                 new \Magento\Framework\Phrase("You can not refund shipping if there is no shipping amount.",[])
             );