Open Radar

 
Summary:
The app I work on requires a shipping address when checking out with Apple Pay but does not require shipping methods because it is a delivery service so there is no shipping. However, when implementing the `didSelectShippingContact` delegate of `PKPaymentAuthorizationViewControllerDelegate` if it returns `[]` for shipping methods, then PassbookUI crashes with the attached log.

Sample project as well is here https://github.com/keithnorm/apple-pay-crash

Steps to Reproduce:
1. either download and configure my sample project to work with your apple pay merchant, or create a basic apple pay button that opens a `PKPaymentAuthorizationViewController` whose delegate implements this:

```
    func paymentAuthorizationViewController(controller: PKPaymentAuthorizationViewController, didSelectShippingContact contact: PKContact, completion: (PKPaymentAuthorizationStatus, [PKShippingMethod], [PKPaymentSummaryItem]) -> Void) {
        completion(.Success, [], [PKPaymentSummaryItem(label: "summary 1", amount: 10.0)])
    }
```
2. run the app, hit "Buy with Apple Pay"
3. select shipping address, hit back
4. Apple Pay modal crashes

Expected Results:
Ideally returning an empty array for shipping methods would not crash and would not render an empty row in the apple pay modal.

Actual Results:
crashes on 9.2, renders empty row on other versions