User is being asked to enter Apple ID twice during the purchase

### Platform

- [x] iOS

### In app purchase type

- [x] Non-consumable
- [x] Auto-Renewable Subscription

### Environment

- [x] Sandbox

### Version

0.13.3

## Report

### Issue summary

I'm using the following snippet for the subscription purchases:
```
SwiftyStoreKit.purchaseProduct("my-product", quantity: 1, atomically: true) { result in
switch result {
case .success(let product):
if product.needsFinishTransaction {
SwiftyStoreKit.finishTransaction(product.transaction)
}
let appleValidator = AppleReceiptValidator(service: .production, sharedSecret: secret)

SwiftyStoreKit.verifyReceipt(using: appleValidator) { result in
switch result {
case .success(let receipt):
let purchaseResults = SwiftyStoreKit.verifySubscriptions(ofType: .autoRenewable, productIds: Set(subscriptionService.productIDs), inReceipt: receipt)

switch purchaseResults {
case .purchased(let expiryDate, let items):
...
```

Here I'm being asked for iTunes Store login twice. First when the purchase is being performed using `purchaseProduct ` and second when I'm retrieving subscriptions from the receipts using `verifyReceipt` and `verifySubscriptions`. It's going to be confusing for users to enter Apple ID twice. Has anyone else seen this behavior?