Comment 13 for bug 1687096

Reviewed: https://review.opencontrail.org/30919
Committed: http://github.com/Juniper/contrail-controller/commit/0d5d2cc122ee8da541599b7bfe884d8d89e247a1
Submitter: Zuul (<email address hidden>)
Branch: R3.2

commit 0d5d2cc122ee8da541599b7bfe884d8d89e247a1
Author: Ananth Suryanarayana <email address hidden>
Date: Mon May 1 15:52:14 2017 -0700

Drop new xmpp connection for existing connection with same name

If the IP address is different, then it implies mis-configuration of
the xmpp agents. In such cases, drop new connection request and
retain existing connection intact

Since xmpp tasks run concurrently (across different IP addresses),
use a XmppConnectionManager scoped mutex to solve concurrency issues
among such parallel xmpp connection requests processing

Also increase severity of a couple of related log messages

Re-enable and fix few UTs that test this very exact scenario

Closes-Bug: #1687096

Change-Id: Ic7252060abfc4b34fa184ff163afc217a88bb40c