Allow nullable fields in the HandlingFeeTax objects

Author: mvgreen

src/test/kotlin/com/ecwid/apiclient/v3/rule/nullablepropertyrules/FetchedOrderRules.kt

@@ -9,6 +9,9 @@ val fetchedOrderNullablePropertyRules: List<NullablePropertyRule<*, *>> = listOf
 	AllowNullable(FetchedOrder.BaseOrderItemTax::name),
 	AllowNullable(FetchedOrder.BaseOrderItemTax::total),
 	AllowNullable(FetchedOrder.BaseOrderItemTax::value),
+	AllowNullable(FetchedOrder.HandlingFeeTax::name),
+	AllowNullable(FetchedOrder.HandlingFeeTax::total),
+	AllowNullable(FetchedOrder.HandlingFeeTax::value),
 	AllowNullable(FetchedOrder::latestShipDate),
 	IgnoreNullable(FetchedOrder::publicUid),
 	IgnoreNullable(FetchedOrder.CreditCardStatus::avsMessage),