Fix bug in test for distributed datastore

The test compared two normalized nodes using toString representation.
This is wrong since these nodes contain hash map and their order(also toString) changes depending on their content.
THe test compared two normalized nodes that did not contain same values. There was Integer in one and Long in the other.

The test failed for me on (due to hash map ordering):
java version "1.7.0_60"
Java(TM) SE Runtime Environment (build 1.7.0_60-b19)
Java HotSpot(TM) 64-Bit Server VM (build 24.60-b09, mixed mode)

Change-Id: Ib72c871077f79cff8327da9c57cc1faa8677a298
Signed-off-by: Maros Marsalek <mmarsale@cisco.com>