Update attribute vat_id frontend_label

Value is `VAT number` while translation string is `VAT Number`.

Author: Jeroen

app/code/Magento/Customer/Setup/UpgradeData.php

@@ -155,6 +155,10 @@ public function upgrade(ModuleDataSetupInterface $setup, ModuleContextInterface
             );
         }
 
+        if (version_compare($context->getVersion(), '2.0.12', '<')) {
+            $this->upgradeVersionTwoZeroTwelve($customerSetup);
+        }
+
         $indexer = $this->indexerRegistry->get(Customer::CUSTOMER_GRID_INDEXER_ID);
         $indexer->reindexAll();
         $this->eavConfig->clear();
@@ -636,6 +640,15 @@ private function upgradeVersionTwoZeroSeven($customerSetup)
         );
     }
 
+    /**
+     * @param CustomerSetup $customerSetup
+     * @return void
+     */
+    private function upgradeVersionTwoZeroTwelve($customerSetup)
+    {
+        $customerSetup->updateAttribute('customer_address', 'vat_id', 'frontend_label', 'VAT Number');
+    }
+
     /**
      * @param ModuleDataSetupInterface $setup
      * @return void