Cloudflare Credentials default values not being set

Problem/Motivation

In a recent update, the default values for the form fields were updated from using ?: operator to the ?? operator. This no longer properly set the default values for the form fields.

Steps to reproduce

1. Navigate to the Cloudflare Credentials form
2. Enter in a Zone ID and Authorization
3. Click "Save configuration"

Proposed resolution

Revert the ?? operator back to the ?: operator