tls: fix macro to check NPN feature

In order to check if NPN feature is enabled, use
`#ifndef OPENSSL_NO_NEXTPROTONEG` rather than
`#ifdef OPENSSL_NPN_NEGOTIATED` because the former is used in ssl.h.

Fixes: https://github.com/nodejs/node/issues/11650
PR-URL: https://github.com/nodejs/node/pull/11655


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Fedor Indutny <fedor@indutny.com>