test: fix test-https-agent-session-eviction for 1.1

This test is testing the workaround for an OpenSSL 1.0.x bug, which was
fixed in 1.1.0. With the bug fixed, the test expectations need to change
slightly.

PR-URL: https://github.com/nodejs/node/pull/16130
Backport-PR-URL: https://github.com/nodejs/node/pull/18622


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Rod Vagg <rod@vagg.org>