CBQE-0: py-swaprebalance.conf optimization

Change-Id: I6832a878b1591f8b5e02a8d41915a78e88777bae
Reviewed-on: http://review.couchbase.org/25754
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Ketaki Gangal <ketakigangal@gmail.com>