fixes:
  - >
    [`bug 1613466 <https://bugs.launchpad.net/keystone/+bug/1613466>`_]
    Credentials update to ec2 type originally accepted credentials with no
    project ID set, this would lead to an error when trying to use such credential.
    This behavior has been blocked, so creating a non-ec2 credential with no
    project ID and updating it to ec2 without providing a project ID will fail with
    a `400 Bad Request` error.
