Bug: remove call to not existing model (#5094)

Author: sreichel

.phpstan.dist.baseline.neon

@@ -162,12 +162,6 @@ parameters:
 			count: 1
 			path: app/code/core/Mage/Adminhtml/Block/Review/Grid/Filter/Type.php
 
-		-
-			rawMessage: 'Call to method getIsOldCustomer() on an unknown class Mage_Adminhtml_Model_Quote.'
-			identifier: class.notFound
-			count: 1
-			path: app/code/core/Mage/Adminhtml/Block/Sales/Order/Create/Newsletter.php
-
 		-
 			rawMessage: 'Call to an undefined method Mage_Shipping_Model_Carrier_Abstract::isGirthAllowed().'
 			identifier: method.notFound

app/code/core/Mage/Adminhtml/Block/Sales/Order/Create/Newsletter.php

@@ -41,10 +41,6 @@ public function getHeaderCssClass()
      */
     protected function _toHtml()
     {
-        if (!Mage::getSingleton('adminhtml/quote')->getIsOldCustomer()) {
-            return parent::_toHtml();
-        }
-
         return '';
     }
 }