[config] Fix Kazoo client mock for unit test
[config] Fix Kazoo client mock for unit test

Sometimes config unit tests failed due to an error in the RabbitMQ
client. It's due to a bug in the Kazoo client mock used by unit tests.

Change-Id: I8bdaa3bc2b60682ae3e7dd10aa94742472b2beb3
Closes-Bug: #1759891

eonpatapon/contrail-controller,rombie/contrail-controller,eonpatapon/contrail-controller,rombie/contrail-controller,rombie/contrail-controller,rombie/contrail-controller,eonpatapon/contrail-controller,rombie/contrail-controller,eonpatapon/contrail-controller,eonpatapon/contrail-controller,rombie/contrail-controller,rombie/contrail-controller,eonpatapon/contrail-controller,eonpatapon/contrail-controller