Call to restore purchase on macOS 11.2, return "Nothing to Restore"

## Bug Report
Call Restore Purchase on macOS 11.2, return "Nothing to Restore", and then receive a callback to restore purchase in the completion function. Actually, you have already purchased. The sample code and terminal print information are as follows:

```
func applicationDidFinishLaunching(_ aNotification: Notification) {
SwiftyStoreKit.completeTransactions(atomically: true) { purchases in
print("completeTransactions:", purchases)
for purchase in purchases {
switch purchase.transaction.transactionState {
case .purchased, .restored:
if purchase.needsFinishTransaction {
// Deliver content from server, then:
SwiftyStoreKit.finishTransaction(purchase.transaction)
}
case .failed, .purchasing, .deferred:
break // do nothing
}
}
}

SwiftyStoreKit.restorePurchases(atomically: true) { results in
if results.restoreFailedPurchases.count > 0 {
print("Restore Failed: \(results.restoreFailedPurchases)")
}
else if results.restoredPurchases.count > 0 {
print("Restore Success: \(results.restoredPurchases)")
}
else {
print("Nothing to Restore")
}
}
}
```

`Terminal Response：`

```
Nothing to Restore
Finishing transaction for payment "com.app.lifetime" with state: restored
completeTransactions: [SwiftyStoreKit.Purchase(productId: "com.app.lifetime", quantity: 1, transaction: productId: com.app.lifetime, transactionId: 1000000772090167, state: restored, date: Optional(2021-02-01 07:31:12 +0000), originalTransaction: Optional(productId: com.app.lifetime, transactionId: 1000000769635443, state: purchased, date: Optional(2021-01-26 02:57:38 +0000)), needsFinishTransaction: false)]
```

**To Reproduce**

**Expected behavior**
A clear and concise description of what you expected to happen.

## Platform Information

- OS: macOS 11.1
- Purchase Type: [non-consumable, auto-renewable subscription]
- Environment: [sandbox, production]
- SwiftyStoreKit version: [0.16.1]

**Potentially Related Issues**