refactor: Article -> set nettoSubSum in constructor

src/QUI/ERP/Accounting/Article.php

@@ -187,6 +187,7 @@ public function __construct($attributes = [])
             $this->nettoPrice      = $calc['nettoPrice'];
             $this->nettoBasisPrice = $calc['nettoBasisPrice'];
             $this->nettoSum        = $calc['nettoSum'];
+            $this->nettoSubSum     = $calc['nettoSubSum'];
 
             $this->vatArray = $calc['vatArray'];
             $this->isEuVat  = $calc['isEuVat'];