Transaction fails to run because country does not have postal code

I have a commerce site that throws an error when a user's billing address is in Ireland. When attempting to submit billing information, including credit card information, the form displays the following error.
"We cannot process your credit card payment without a valid billing address."

I looked into it and the issue appears to be around line 502 in commerce_hosted_pci.module.

    foreach (array('thoroughfare', 'locality', 'postal_code', 'country') as $address_key) {
      if (empty($address_value[$address_key])) {
        $valid_billing_address = FALSE;
      }
    }

This code assumes any address should have these fields.