Purchase function returns success without purchasing product

## Bug Report
Calling SwiftyStoreKit.purchaseProduct does not show purchase dialog
It return callback with success with old transaction details

**To Reproduce**
Steps to reproduce the behaviour:

1. Existing subscription status is EXPIRED
2. User try to buy a new subscription
2. Call SwiftyStoreKit.purchaseProduct
3. callback return success with old transaction details without showing purchase dialog

**Expected behaviour**
After calling SwiftyStoreKit.purchaseProduct app should display purchase dialog

## Platform Information
- iOS 15.1
- Purchase Type: auto-renewable subscription
- Environment: TestFlight
- SwiftyStoreKit version: 0.16.1

## Additional context
Very in-consistent issue reproduced for some of the users