test: move require http2 to after crypto check

Currently test-http2-client-write-empty-string.js will throw "Error
[ERR_NO_CRYPTO]: Node.js is not compiled with OpenSSL crypto support"
when configured --without-ssl.

This commit moves the require of http2 to after the crypto check to
avoid this error.

Backport-PR-URL: https://github.com/nodejs/node/pull/22380
PR-URL: https://github.com/nodejs/node/pull/19111


Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>