update list of nodes if master node is down
update list of nodes if master node is down

Change-Id: I60f235b363fc3e08bac9ce66f2a58b9fe0da33fa
Reviewed-on: http://review.couchbase.org/24695
Tested-by: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Pavel Paulau <dd88eded64e90046a680e3a6c0828ceb8fe8a0e7@gmail.com>

couchbase/cbagent,couchbase/cbmonitor,couchbase/cbmonitor,mikewied/cbagent,pavel-paulau/cbagent,vmx/cbagent,ronniedada/litmus,ronniedada/litmus