https: prevent options object from being mutated

Previously, when passing options object to the agent.createConnection
method, the same options object got modified within the method. Now,
any modification will happen on only a copy of the object.

Fixes: https://github.com/nodejs/node/issues/31119

PR-URL: https://github.com/nodejs/node/pull/31151


Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>