test: fix test-tls-securepair-client

test-tls-securepair-client has been failing for over a year but no one
noticed because pummel tests are almost never run.

In preparation for running pummel tests once a day in CI, fix
test-tls-securepair-client.

PR-URL: https://github.com/nodejs/node/pull/25222


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>