Enable multi-threaded nova-conductor
Enable multi-threaded nova-conductor

Just like I09f4c6f57e71982b8c7fc92645b3ebec12ff1348, enable
multi-threaded nova-conductor.  This feature was merged into nova in
I8698997d211d7617ee14a1c6113056a694d70620.

Change-Id: Id7042284e81bd64092a400d24a3170ce07beb08c

noironetworks/devstack,eharney/devstack,NaokiMiyata/devstack,richliu/devstack,sc68cal/devstack,affo/devstack,thomasem/devstack,wenhuizhang/devstack,parul24/devstack,neerja28/Devstack_GlusterFS,costingalan/devstack,thomasem/devstack,Millnert/contrail-devstack,mc2014/devstack,dtroyer/devstack,prithivm/branch01,bswartz/devstack,jamielennox/devstack,olivierlemasle/devstack,avvocatodemarchis/devstack,upadhyay-prashant/devstack,mc2014/devstack,vishnugonela/devstack,innodee/openstackk,varunarya10/devstack,BSJAIN92/OpenStack,bljgaurav/openstack-test,CloudServer/devstack,dirkmueller/devstack,mmasaki/devstack,nawawi/openstack,HPCHub/devstack,nuxeh/devstack,vishnugonela/devstack,mssumanth/devstack,nuxeh/devstack,vsham20/devstack,upadhyay-prashant/devstack,samgoon/devstack,pczerkas/devstack,bswartz/devstack,pombredanne/devstack,avvocatodemarchis/devstack,wenhuizhang/devstack,BSJAIN92/OpenStack,rushiagr/devstack,ozamiatin/devstack,JioCloud/devstack,kplus/devstack-moonshot,ozamiatin/devstack,liuquansheng47/devstack,j4/devstack,sequenceiq/devstack,williamthegrey/devstack,olivierlemasle/devstack,CloudServer/devstack,parul24/devstack,bigswitch/devstack,neerja28/Devstack_GlusterFS,mmasaki/devstack,richliu/devstack,openstack-dev/devstack,group-policy/devstack,Mahito/devstack,affo/devstack,herrsechs/devstack,varunarya10/devstack,TwinkleChawla/devstack,noironetworks/devstack,pacinete/devstack,HPCHub/devstack,pombredanne/devstack,eshnil2000/devstack,virtualopensystems/devstack,andrewrothstein/devstack,mssumanth/devstack,TwinkleChawla/devstack,j4/devstack,bq-xiao/devstack,flavio-fernandes/devstack,pczerkas/devstack,rushiagr/devstack,sequenceiq/devstack,bigswitch/devstack,pacinete/devstack,bljgaurav/openstack-test,dirkmueller/devstack,herrsechs/devstack,andrewrothstein/devstack,sc68cal/devstack,prithivm/branch01,tianweizhang/devstack,tianweizhang/devstack,bq-xiao/devstack,atulpatil301/devstack,srics/devstack,nawawi/openstack,flavio-fernandes/devstack,promptworks/devstack,LoHChina/devstack,LoHChina/devstack,costingalan/devstack,atulpatil301/devstack,kplus/devstack-moonshot,promptworks/devstack,samgoon/devstack,openstack-dev/devstack,eharney/devstack,dtroyer/devstack,group-policy/devstack,NaokiMiyata/devstack,Mahito/devstack,Juniper/devstack,liuquansheng47/devstack,yamt/devstack,vsham20/devstack