http2: don't expose the original socket through the socket proxy

Refs: https://github.com/nodejs/node/pull/22486

PR-URL: https://github.com/nodejs/node/pull/22650


Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: James M Snell <jasnell@gmail.com>