MAGNIMEX-316: Fix bug incorrect labels for images of product

Author: Dmitry Kologrivov

app/code/Magento/CatalogImportExport/Model/Import/Product.php

@@ -1414,7 +1414,9 @@ protected function _saveProducts()
                             && !in_array($rowData[$imageCol], $mediaGalleryImages)) {
                             $mediaGalleryImages[] = $rowData[$imageCol];
                             if (isset($mediaGalleryLabels)) {
-                                $mediaGalleryLabels[] = isset($rowData[$imageCol . '_label']);
+                                $mediaGalleryLabels[] = isset($rowData[$imageCol . '_label'])
+                                ? $rowData[$imageCol . '_label']
+                                : '';
                             } else {
                                 $mediaGalleryLabels[] = '';
                             }