Fix logging of certificate chain errors.

[jupacaza]

Use comma-separated list to format the logged string.

Fix logging of certificate chain errors.

• [x] You've read the Contributor Guide and Code of Conduct.
• [x] You've included unit or integration tests for your change, where applicable.
• [x] You've included inline docs for your change, where applicable.
• [x] There's an open issue for the PR that you are making. If you'd like to propose a new feature or change, please open an issue to discuss the change or find an existing issue.

Summary of the changes (Less than 80 chars)

Description

Without this the log just says: "System.Collections.Generic.List1[System.String]".

Fixes #44484

[ghost]

Thanks for your PR, @jupacaza. Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[HaoK]

Thanks for this PR @jupacaza !