Check for deleted AgentXmppChannel while updating new set of XmppServers learnt by Discovery.
Note, we delete the AgentXmppChannel in the same loop while configuring new connections.

Change-Id: Ie41dbd1c462e63686d182800c68fe1e42da223e0
Merge "Check for deleted AgentXmppChannel while updating new set of XmppServers learnt by Discovery. Note, we delete the AgentXmppChannel in the same loop while configuring new connections."