title: Stripe Apple Pay crash due to format does not match expected client secret
body: <p>While using stripe apple pay when i make payment then app crash and showing error &quot;Assertion failed: <code>secret</code> format does not match expected client secret formatting.: file Stripe/STPAPIClient.swift, line 593&quot;</p>
  <pre><code> let paymentRequest = StripeAPI.paymentRequest(withMerchantIdentifier: STPPaymentConfiguration.shared.appleMerchantIdentifier!, country: &quot;US&quot;, currency: &quot;USD&quot;)
  
      paymentRequest.paymentSummaryItems = [
          PKPaymentSummaryItem(label: &quot;iTem 1&quot;, amount: NSDecimalNumber(value: 10.0))),
      ]
      
      // Initialize an STPApplePayContext instance
      if let applePayContext = STPApplePayContext(paymentRequest: paymentRequest, delegate: self) {
          // Present Apple Pay payment sheet
          applePayContext.presentApplePay(on: self)
      }
      else{
          // There is a problem with your Apple Pay configuration
          let alert = self.showAlert(withTitle: &quot;Error&quot;, andMessage:&quot;Unable to make Apple Pay transaction.&quot;, completion: self.alertAction)
          self.present(alert, animated: true)
  </code></pre>