http: don't destroy completed request

Calling destroy() on a completed ClientRequest, i.e.
once 'close' will be emitted should be a noop. Also
before emitting 'close' destroyed === true.

Fixes: https://github.com/nodejs/node/issues/32851

PR-URL: https://github.com/nodejs/node/pull/33120


Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>