test: move require of http2 to after crypto check

Currently when configured without-ssl test-heapdump-http2.js will fail
with a missing crypto message.
This commit moves the require of http2 to after the crypto check.

PR-URL: https://github.com/nodejs/node/pull/22148


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>