bug 980725: multi_host is always set to True with virtdriver=xenserver
bug 980725: multi_host is always set to True with virtdriver=xenserver

set MULTI_HOST according to the value as defined in localrc or other rc files.

Change-Id: Ifc5d0fff06bffd39ab4ff1c1a6fa5d4ab10b9e27

williamthegrey/devstack,NaokiMiyata/devstack,kplus/devstack-moonshot,thomasem/devstack,eharney/devstack,ewindisch/raspi-devstack,LoHChina/devstack,upadhyay-prashant/devstack,wenhuizhang/devstack,BSJAIN92/OpenStack,herrsechs/devstack,ykaneko/devstack,CloudServer/devstack,openstack-dev/devstack,neerja28/Devstack_GlusterFS,bljgaurav/openstack-test,costingalan/devstack,samgoon/devstack,richliu/devstack,vishnugonela/devstack,tianweizhang/devstack,savi-dev/devstack,atulpatil301/devstack,j4/devstack,Yuriy-Leonov/devstack,NaokiMiyata/devstack,HPCHub/devstack,bigswitch/devstack,prithivm/branch01,pczerkas/devstack,affo/devstack,andrewrothstein/devstack,andrewrothstein/devstack,samgoon/devstack,mc2014/devstack,mssumanth/devstack,ozamiatin/devstack,bq-xiao/devstack,flavio-fernandes/devstack,TwinkleChawla/devstack,vsham20/devstack,nttmcl/devstack_public,r-mibu/devstack,group-policy/devstack,promptworks/devstack,Juniper/devstack,wenhuizhang/devstack,parul24/devstack,nawawi/openstack,CiscoSystems/devstack,bq-xiao/devstack,rushiagr/devstack,parul24/devstack,virtualopensystems/devstack,citrix-openstack-build/devstack,armando-migliaccio/devstack,vishnugonela/devstack,eharney/devstack,innodee/openstackk,varunarya10/devstack,nuxeh/devstack,noironetworks/devstack,ozamiatin/devstack,ewindisch/raspi-devstack,pacinete/devstack,citrix-openstack-build/devstack,mc2014/devstack,noironetworks/devstack,herrsechs/devstack,Mahito/devstack,dirkmueller/devstack,liuquansheng47/devstack,pombredanne/devstack,j4/devstack,avvocatodemarchis/devstack,inkerra/devstack,thomasem/devstack,ykaneko/devstack,dtroyer/devstack,costingalan/devstack,pombredanne/devstack,CloudServer/devstack,sstrato/devstack,avvocatodemarchis/devstack,srics/devstack,TwinkleChawla/devstack,mmasaki/devstack,atulpatil301/devstack,Millnert/contrail-devstack,varunarya10/devstack,group-policy/devstack,upadhyay-prashant/devstack,neerja28/Devstack_GlusterFS,dtroyer/devstack,dirkmueller/devstack,bswartz/devstack,BSJAIN92/OpenStack,kplus/devstack-moonshot,promptworks/devstack,rushiagr/devstack,sequenceiq/devstack,sc68cal/devstack,pacinete/devstack,affo/devstack,nati/devstack_public,richliu/devstack,pczerkas/devstack,liuquansheng47/devstack,vsham20/devstack,Mahito/devstack,shootstar/devstacktest,sequenceiq/devstack,savi-dev/devstack,JioCloud/devstack,jamielennox/devstack,nuxeh/devstack,olivierlemasle/devstack,eshnil2000/devstack,LoHChina/devstack,sc68cal/devstack,bswartz/devstack,r-mibu/devstack,nati/devstack_public,olivierlemasle/devstack,nawawi/openstack,tianweizhang/devstack,prithivm/branch01,openstack-dev/devstack,bigswitch/devstack,cloudbuilders/devstack,nttmcl/devstack_public,mssumanth/devstack,mmasaki/devstack,deepakselvaraj/devstack,cloudbuilders/devstack,flavio-fernandes/devstack,yamt/devstack,HPCHub/devstack,bljgaurav/openstack-test