test: fixup test-http2-create-client-secure-session

General improvements to test and verify that a secureConnect
handler is present

PR-URL: https://github.com/nodejs/node/pull/17328
Fixes: https://github.com/nodejs/node/issues/15303


Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Sebastiaan Deckers <sebdeckers83@gmail.com>