Fix intermittent ToasterTest failures

The ToasterTest has been intermittently failing on jenkins for a while.
I repro'ed it locally after 5 tries. An error occurs indicating it
can't find the pingpong-databroker namespace. Not sure why this occurs
intermittently.

The test doesn't need/use the pingpong databroker so I commented it out
in the controller.xml. After this change the test ran successfully 80
times.

Change-Id: Id0cfdd2464218173e91392ac9bb66e60a8f51595
Signed-off-by: Tom Pantelis <tpanteli@brocade.com>