Merge pull request #6117 from U-Mebius/dev/fix_tax_rule_error

税率設定時に商品別税率を考慮していないのを修正

src/Eccube/Form/Type/Admin/TaxRuleType.php

@@ -77,6 +77,7 @@ public function buildForm(FormBuilderInterface $builder, array $options)
             $qb
                 ->select('count(t.id)')
                 ->where('t.apply_date = :apply_date')
+                ->andWhere('t.ProductClass IS NULL')
                 ->setParameter('apply_date', $TaxRule->getApplyDate());
 
             if ($TaxRule->getId()) {