Adjust SSL context generation for Server:

The creation of self-signed certificates slows down the command
line client when launched repeatedly during unit test.
* Contexts are no longer generated for the command line client
* A port with no secure protocols generates an empty context

Reviewers: @donovanhide @josh-ripple
Probably needs some comments to explain each conditional. This is security related and it would be easy to make a change in the future that does the wrong thing without some guiding words.