test: add valid tls config tests

What does this MR do?

while reviewing tls test coverage I noticed there are no tests to verify correct tls configuration so I've added it here.

tls test coverage should be 100% with this

TODO

• I added the Changelog trailer (e.g. Changelog: feature) to the commits that need to be included in the changelog
• I added unit tests or they are not required
• I added acceptance tests or they are not required
• I added documentation (or it's not required)
• I followed code review guidelines
• I followed Go Style guidelines