check subject and attribute set before continuing with interceptor

Author: patrikpihlstrom

app/code/Magento/CatalogUrlRewrite/Plugin/Eav/Model/AttributeSetRepository.php

@@ -47,6 +47,11 @@ public function aroundDelete(
         callable $proceed,
         AttributeSetInterface $attributeSet
     ) {
+	if (!isset($subject) || !$attributeSet->getAttributeSetId())
+	{
+		return false;
+	}
+
         // Get the product ids
         $ids = $this->productCollection->addFieldToFilter('attribute_set_id', $attributeSet->getAttributeSetId())
                                        ->getAllIds();