fix(tests/cdn): Make check case insensitive

[bkochendorfer]

One-line summary

This was the only failing test when run locally, just a difference in casing in how the CDN presents this information.

The ssl-labs tests use an external DNS and so cannot test the changes under question. Once deployed we can verify those tests are the same or make adjustments as needed.

Testing

Ran the tests locally pointing at a local /etc/hosts override to test CDN deployment.