Don't suggest to enable encryption when cluster is not 2.5.

Change-Id: Ib37c6dc72f9ffec858de7b00159c2991558be64b
Reviewed-on: http://review.couchbase.org/31833
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Don't create cluster reference with SSL when cluster is not 2.5.

Change-Id: I5924fe23e14c130cb4e1b62ab5b918fb9a072dee
Reviewed-on: http://review.couchbase.org/31835
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>