MB-100: 5 retries when Node is unknown to this cluster

now we use 3 retries when getting 'Node is unknown to this cluster.' in nodes/self h after rebalance out for the node.
It's not a bug, but 3 times is not enough
http://qa.hq.northscale.net/job/centos-64-2.0-rebalance-regressions/178/consoleFull

Change-Id: I7ca7a1e2e8eca14abdc7bd5f95ef0800d52d611e
Reviewed-on: http://review.couchbase.org/24468
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: buildbot <build@couchbase.com>