tls: fix DEP0083 after upgrading to OpenSSL 1.1.0

Setting ecdhCurve to false is already unsupported, so the deprecation
should already be EOL. The test was skipped ever since we upgraded to
OpenSSL 1.1.0.

PR-URL: https://github.com/nodejs/node/pull/22953
Refs: https://github.com/nodejs/node/pull/16130


Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>