IO-2928 Null coalesce billline amount

Signed-off-by: Allan Carr <allan.carr@thinkimex.com>

server/accounting/qbo/qbo-payables.js

@@ -219,7 +219,7 @@ async function InsertBill(oauthClient, qbo_realmId, req, bill, vendor, bodyshop)
       Amount: Dinero({
         amount: Math.round(
           bill.billlines.reduce((acc, val) => {
-            return acc + val.applicable_taxes?.federal ? val.actual_cost * val.quantity : 0;
+            return acc + val.applicable_taxes?.federal ? (val.actual_cost * val.quantity ?? 0) : 0;
           }, 0) * 100
         )
       })