Verify PSC DNS name is present as a SAN in the server certificate

[nancynh]

Verify PSC DNS name is present as a SAN in the server certificate. It means removing the existing workaround to check the private IP address instead of the DNS name (#291).

[jackwotherspoon]

is this a duplicate of #313 ?

[enocom]

Yes, let's use this one for tracking.

[jackwotherspoon]

Good context on the trailing dot being stripped dpkp/kafka-python#2374 (comment)

[jackwotherspoon]

More good context on this thread: openssl/openssl#11560

[enocom]

Thanks to @jackwotherspoon for finding this:

openssl/openssl#11560 (comment)

TL;DR: SANs shouldn't have trailing dots.

[enocom]

RFC 6066 says no trailing dots in SANs.