UPR Issue:: Rebalance-in hangs for build 3.0.0-613

Using vbuckets=64, upr

1. Add 3 nodes to cluster
2. Create default bucket
3. Add 100K Items
4. Rebalance-in one node

Step for rebalance-in, We will rebalance-in 10.6.2.147

Starting rebalance, KeepNodes = ['ns_1@10.6.2.144','ns_1@10.6.2.145',
'ns_1@10.6.2.146','ns_1@10.6.2.147'], EjectNodes = [], Failed over and being ejected nodes = []; no delta recovery nodes

Observation: Rebalance-in never finishes.

The UI logs shows no warning or failure. It is just stuck there. This test was passing in 3.0.0-608.