[system tests] Delta Recovery: Rebalance exited with reason {badmatch, {error, {failed_nodes

steps:
1. 3 nodes in cluster, 4 buckets. run data loader more then a day
2. setup replication from SRC to cluster DEST for all buckets.
3. rebalance in 1 node at SRC cluster and on Dest cluster
4. Graceful Fail Over node on SRC add back with Delta Recovery(rebalance)

result:

Rebalance exited with reason {badmatch,
{error,

}}
ns_orchestrator002 ns_1@172.23.105.207 08:28:42 - Thu Dec 10, 2015
Started rebalancing bucket UserInfo ns_rebalancer000 ns_1@172.23.105.207 08:28:41 - Thu Dec 10, 2015
Bucket "RevAB" loaded on node 'ns_1@172.23.106.125' in 12 seconds. ns_memcached000 ns_1@172.23.106.125 08:28:40 - Thu Dec 10, 2015
Bucket "UserInfo" loaded on node 'ns_1@172.23.106.125' in 12 seconds. ns_memcached000 ns_1@172.23.106.125 08:28:40 - Thu Dec 10, 2015
Bucket "AbRegNums" loaded on node 'ns_1@172.23.106.125' in 12 seconds. ns_memcached000 ns_1@172.23.106.125 08:28:40 - Thu Dec 10, 2015
Bucket "MsgsCalls" loaded on node 'ns_1@172.23.106.125' in 0 seconds. ns_memcached000 ns_1@172.23.106.125 08:28:28 - Thu Dec 10, 2015
Starting rebalance, KeepNodes = ['ns_1@172.23.105.43','ns_1@172.23.105.207',
'ns_1@172.23.105.225','ns_1@172.23.106.125'], EjectNodes = [], Failed over and being ejected nodes = [], Delta recovery nodes = ['ns_1@172.23.106.125'], Delta recovery buckets = all ns_orchestrator004 ns_1@172.23.105.207 08:28:27 - Thu Dec 10, 2015