Remove contrail_discovery from haproxy conf for OC 4.0

Contrail-Discovery service was removed from OpenContrail starting
from version 4.0. This way we need to remove related records from
haproxy configurations for deployments of OC 4.0

Change-Id: Ifa286892041648179b4e2fa7e13ffe8ba4cb4845
Related-Bug: PROD-23817
4 files changed