Don't create cluster reference with SSL when cluster is not 2.5.
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 <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>

membase/ns_server,daverigby/ns_server,daverigby/ns_server,membase/ns_server,mschoch/ns_server,mschoch/ns_server,daverigby/ns_server,t3rm1n4l/ns_server,mschoch/ns_server,membase/ns_server,ceejatec/ns_server,ceejatec/ns_server,nimishzynga/ns_server,ceejatec/ns_server,ceejatec/ns_server,nimishzynga/ns_server,membase/ns_server,membase/ns_server,ceejatec/ns_server,ceejatec/ns_server,membase/ns_server,t3rm1n4l/ns_server,t3rm1n4l/ns_server,nimishzynga/ns_server,mschoch/ns_server,mschoch/ns_server,mschoch/ns_server,t3rm1n4l/ns_server,t3rm1n4l/ns_server,daverigby/ns_server,daverigby/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,nimishzynga/ns_server