Verify Receipt fails for Apple Reviewer and keeps on rejecting app (Error: SwiftyStoreKit.ReceiptError error 2).

## Bug Report
After successful purchase, Verify Receipt Works for us, but not for Apple reviewer. They are getting below error and keeps on rejecting app.
(SwiftyStoreKit.ReceiptError error 2).

**To Reproduce**
```
SwiftyStoreKit.verifyReceipt(using: appleValidator) { result in
if case .success(let receipt) = result {
...

} else if case .error(let error) = result {
// Always comes here and shows error
}

```
**Expected behavior**
Should come in success block and proceed further. Purchase is successful, verify receipt is failing.

## Platform Information
- OS: iOS 13.5.1
- Purchase Type: auto-renewable subscription
- Environment: Sandbox and app review
- SwiftyStoreKit version: 0.13.3

**Screenshots**

Start at SwiftyStoreKit.verifyReceipt(using: appleValidator) and investigate why the reported SwiftyStoreKit.ReceiptError error 2 occurs for Apple review purchases but not the reporter’s successful purchases. Compare the Sandbox and app review environments and the auto-renewable subscription flow. Done means the reviewer’s receipt reaches the success path rather than the error branch.

Written by the indexing model from the issue text.