Fix bug when legacy NPN is tested against a TLS 1.3 host

[drwetter]

Describe your changes

When testing a TLS 1.3 host s_client_options used TLS 1.3 ciphers to test for NPN. As that is not implemented we nee dto make sure any other version is used.

This PR ensures that --after testing whether it's a TLS 1.3-only host where this test doesn't make any sense in the first place.

Fix for #2633 (3.0)

What is your pull request about?

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Typo fix
• Documentation update
• Update of other files

If it's a code change please check the boxes which are applicable

• For the main program: My edits contain no tabs and the indentation is five spaces
• I've read CONTRIBUTING.md and Coding_Convention.md
• I have tested this fix against >=2 hosts and I couldn't spot a problem
• I have tested this new feature against >=2 hosts which show this feature and >=2 host which does not (in order to avoid side effects) . I couldn't spot a problem
• For the new feature I have made corresponding changes to the documentation and / or to help()
• If it's a bigger change: I added myself to CREDITS.md (alphabetical order) and the change to CHANGELOG.md