Don't even try to clear pem cache on R14.

Change-Id: Ia406468d0d44a92b18ca247f31bd13efadb4682c
Reviewed-on: http://review.couchbase.org/38468
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>