MAGETWO-43764: When a guest user subscribe, the storeview is not saved/displayed in the admin panel

Author: AndriyNasinnyk

app/code/Magento/Newsletter/Model/ResourceModel/Subscriber/Collection.php

@@ -146,7 +146,8 @@ public function showCustomerInfo()
             [
                 'customer' => $this->getTable('customer_entity')
             ],
-            'main_table.customer_id = customer.entity_id'
+            'main_table.customer_id = customer.entity_id',
+            ['firstname', 'lastname']
         );
         return $this;
     }