Add Task Exclusion for xmpp tasks.
Add Task Exclusion for xmpp tasks.

XMPP needs to have task exclusion for bgp::config task
to bgp::ShowCommand and xmpp::StateMachine

Change-Id: Ibc1a642db25aba51023e5c76f0491f8fe3c8879c

vmahuli/contrail-controller,rombie/contrail-controller,numansiddique/contrail-controller,codilime/contrail-controller,sajuptpm/contrail-controller,sajuptpm/contrail-controller,facetothefate/contrail-controller,numansiddique/contrail-controller,facetothefate/contrail-controller,reiaaoyama/contrail-controller,codilime/contrail-controller,reiaaoyama/contrail-controller,tcpcloud/contrail-controller,numansiddique/contrail-controller,nischalsheth/contrail-controller,eonpatapon/contrail-controller,hthompson6/contrail-controller,hthompson6/contrail-controller,tcpcloud/contrail-controller,facetothefate/contrail-controller,nischalsheth/contrail-controller,sajuptpm/contrail-controller,tcpcloud/contrail-controller,vmahuli/contrail-controller,DreamLab/contrail-controller,hthompson6/contrail-controller,eonpatapon/contrail-controller,codilime/contrail-controller,vpramo/contrail-controller,eonpatapon/contrail-controller,rombie/contrail-controller,nischalsheth/contrail-controller,sajuptpm/contrail-controller,rombie/contrail-controller,reiaaoyama/contrail-controller,reiaaoyama/contrail-controller,sajuptpm/contrail-controller,vpramo/contrail-controller,codilime/contrail-controller,DreamLab/contrail-controller,reiaaoyama/contrail-controller,vpramo/contrail-controller,codilime/contrail-controller,nischalsheth/contrail-controller,nischalsheth/contrail-controller,nischalsheth/contrail-controller,vmahuli/contrail-controller,rombie/contrail-controller,rombie/contrail-controller,eonpatapon/contrail-controller,DreamLab/contrail-controller,vpramo/contrail-controller,vmahuli/contrail-controller,nischalsheth/contrail-controller,numansiddique/contrail-controller,numansiddique/contrail-controller,facetothefate/contrail-controller,hthompson6/contrail-controller,vpramo/contrail-controller,tcpcloud/contrail-controller,facetothefate/contrail-controller,eonpatapon/contrail-controller,tcpcloud/contrail-controller,DreamLab/contrail-controller,rombie/contrail-controller,rombie/contrail-controller,sajuptpm/contrail-controller,nischalsheth/contrail-controller,DreamLab/contrail-controller,hthompson6/contrail-controller,eonpatapon/contrail-controller,eonpatapon/contrail-controller,vmahuli/contrail-controller,tcpcloud/contrail-controller,codilime/contrail-controller