do not start upr_notifier for memcached buckets
do not start upr_notifier for memcached buckets

This unbreaks memcached buckets support

Change-Id: I278fd48a274398e60a91ba904f6244ae43293b92
Reviewed-on: http://review.couchbase.org/35917
Tested-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>
Reviewed-by: Artem Stemkovski <15a0730a27c69f62ab86f2b6c639fca202166c02@couchbase.com>

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