nova: use the correct notification driver
nova: use the correct notification driver

Nova now uses oslo.messaging and not the Oslo RPC code anymore,
therefore the new driver should be used instead.

Change-Id: I3533975ad38ff99bee6cfaa5332843444650f61f

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