Launch screen with bash as shell
Launch screen with bash as shell

Since screen commands are bash specifics make sure we launch screen with
bash login shell instead of other shells.

Fixes bug928883.

Change-Id: I62b4c7182682deb4ef16ed0cf1a3b5a130c1c4ee

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