Issue: When both discovery IP and service IP is configured in contrail-vrouter-agent.conf, the expected_connections count (used by NodeStatus UVE to declare whether agent is Functional or not) computed by agent was incorrect.
Fix: While updating expected_connections count we should consider whether agent has subscribed for a given discovery service or not.
Closes-Bug: #1396164

Change-Id: Idbef7de5e63bec52dbeb50547ed61ba37255c288
(cherry picked from commit 3aa2e2ea19d3dea52d1e18346947c152df6c4d6c)