deps: float a9cfb8c2 from openssl (CVE-2018-0734)

Low severity timing vulnerability in the DSA signature algorithm

Publicly disclosed but unreleased, pending OpenSSL 1.1.0j

Ref: https://github.com/openssl/openssl/pull/7486
Ref: https://www.openssl.org/news/secadv/20181030.txt
PR-URL: https://github.com/nodejs/node/pull/???
Upstream: https://github.com/openssl/openssl/commit/a9cfb8c2



Original commit message:

    Avoid a timing attack that leaks information via a side channel that
    triggers when a BN is resized.  Increasing the size of the BNs
    prior to doing anything with them suppresses the attack.

    Thanks due to Samuel Weiser for finding and locating this.

Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
    (Merged from https://github.com/openssl/openssl/pull/7486)

PR-URL: https://github.com/nodejs/node/pull/23965


Reviewed-By: Ujjwal Sharma <usharma1998@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>