[longevity] Rebalance exited with reason bulk_set_vbucket_state_failed

add 6 nodes to cluster and do rebalance
load 200K items
remove 5 nodes, start rebalance
rebalance is failed

Rebalance exited with reason {bulk_set_vbucket_state_failed,
[{'ns_1@10.2.2.60',
{'EXIT',
{timeout,
{gen_server,call,
[

{'janitor_agent-default','ns_1@10.2.2.60'}

,

{update_vbucket_state,<0.26047.9>,65, replica,passive,undefined}

,
30000]}}}}]}