CBQE-923 Modify reproducer test case

Fix with cluster_run, init_nodes before rebalance

Change-Id: I28a67409770a5975050a9352591aea4a07710f57
Reviewed-on: http://review.couchbase.org/23547
Reviewed-by: Deepkaran Salooja <deepkaran.salooja@globallogic.com>
Tested-by: Deepkaran Salooja <deepkaran.salooja@globallogic.com>