CBQE-1851: added support for xdcr encryption after upgrade to 2.5

Change-Id: I9f6eaa290b20075003275e97e971dfd17a21e85e
Reviewed-on: http://review.couchbase.org/32537
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Reviewed-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>
Tested-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>