Remove unused variables in os_swift role
Remove unused variables in os_swift role

swift_service_admin_username and swift_service_admin_tenant_name
are not used anywhere. The correct (and used) variables for the
purpose are swift_service_user_name and swift_service_project_name

Change-Id: I26cbbb77ddbf46fa64d8d34e5625590f3f66c515
Closes-Bug: #1460497

jpmontez/openstack-ansible,sti-jans/openstack-ansible,robb-romans/openstack-ansible,antonym/openstack-ansible,jpmontez/openstack-ansible,pombredanne/os-ansible-deployment,antonym/openstack-ansible,manuelfelipe/openstack-ansible,open-switch/infra_openstack-ansible,jpmontez/os-ansible-deployment,major/openstack-ansible,yanyao/openstack-deployment-liberty,Logan2211/openstack-ansible,BjoernT/os-ansible-deployment,pombredanne/os-ansible-deployment,openstack/openstack-ansible,mrda/openstack-ansible,open-switch/infra_openstack-ansible,open-switch/infra_openstack-ansible,BjoernT/openstack-ansible,major/os-ansible-deployment,yanyao/openstack-deployment-liberty,manuelfelipe/openstack-ansible,sti-jans/openstack-ansible,major/openstack-ansible,BjoernT/os-ansible-deployment,shane-c/openstack-ansible,mancdaz/openstack-ansible,manuelfelipe/openstack-ansible,git-harry/os-ansible-deployment,achekunov/openstack-ansible,jpmontez/os-ansible-deployment,weezer/openstack-ansible,shane-c/openstack-ansible,os-cloud/os-ansible-deployment,mrda/openstack-ansible,cloudnull/os-ansible-deployment,yanyao/newton,yanyao/openstack-deployment-liberty,openstack/openstack-ansible,AlphaStaxLLC/os-ansible-deployment,yanyao/newton,stackforge/os-ansible-deployment,git-harry/os-ansible-deployment,antonym/openstack-ansible,AlphaStaxLLC/os-ansible-deployment,git-harry/os-ansible-deployment,sti-jans/openstack-ansible,BjoernT/os-ansible-deployment,cloudnull/os-ansible-deployment,yanyao/openstack-ansible,mrda/openstack-ansible,major/os-ansible-deployment,achekunov/openstack-ansible,mancdaz/openstack-ansible,stackforge/os-ansible-deployment,cfarquhar/openstack-ansible,jpmontez/os-ansible-deployment,yanyao/openstack-ansible,jpmontez/openstack-ansible,bunchc/openstack-ansible,shane-c/openstack-ansible,os-cloud/os-ansible-deployment,pombredanne/os-ansible-deployment,achekunov/openstack-ansible,bunchc/openstack-ansible,AlphaStaxLLC/os-ansible-deployment,robb-romans/openstack-ansible,BjoernT/openstack-ansible,weezer/openstack-ansible,Logan2211/openstack-ansible,cfarquhar/openstack-ansible