Make SSL trace logging less verbose

Filter things that might be significant, but not lower level details of
openssl itself (otherwise the logs are _huge_).

Change-Id: I4c4232419bd1d5287327c9cd3e0482a87c049840
Reviewed-on: http://review.couchbase.org/42146
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Mark Nunberg <mnunberg@haskalah.org>