MAGETWO-34174: CI builds stabilization

Author: Yurii Torbyk

app/code/Magento/Sales/Model/AdminOrder/Create.php

@@ -1915,7 +1915,7 @@ protected function _validate()
             foreach ($this->_errors as $error) {
                 $this->messageManager->addError($error);
             }
-            throw new \Magento\Framework\Exception\LocalizedException(__(''));
+            throw new \Magento\Framework\Exception\LocalizedException(__('Validation is failed.'));
         }
 
         return $this;

app/code/Magento/Wishlist/Model/Item.php

@@ -431,7 +431,7 @@ public function addToCart(\Magento\Checkout\Model\Cart $cart, $delete = false)
         }
 
         if (!$product->isSalable()) {
-            throw new ProductException(__(''));
+            throw new ProductException(__('Product is not salable.'));
         }
 
         $buyRequest = $this->getBuyRequest();