[35897] In the HAProxy configuration for the contrail-api service,
changed the default balance method from roundrobin to leastconn.
This prevents a performance issue from occurring if several heavy requests
are redirected to the same contrail-api worker. Using the leastconn
balancing method, the request is scheduled to a worker with the least
active sessions to avoid performance issues when several requests are
queueing at one worker.
[35747] Fixed the issue with an unstable connection between the RabbitMQ
server and the OpenContrail controller nodes.