LU-8602 gss: support OpenSSL 1.1

LU-8602 gss: support OpenSSL 1.1

Add support for OpenSSL 1.1, used by default on Ubuntu 18.04.

It mainly consists in changing the way variables of type DH
and HMAC_CTX are used.

Test-Parameters: testlist=sanity-sec envdefinitions=SHARED_KEY=true
Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: I1fc9b77fc44976f4b1fb3a58ae7db9c20a96b3e9
Reviewed-on: https://review.whamcloud.com/33592
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: John L. Hammond <jhammond@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>