Fixes grammar in setup.rst in doc source
Fixes grammar in setup.rst in doc source

Change-Id: I42b6a3a18c40c1889f1bfaf6c526b5a959ca591c

mahak/keystone,dims/keystone,klmitch/keystone,takeshineshiro/keystone,himanshu-setia/keystone,rajalokan/keystone,openstack/keystone,mahak/keystone,maestro-hybrid-cloud/keystone,dims/keystone,ilay09/keystone,mahak/keystone,ajayaa/keystone,vivekdhayaal/keystone,vivekdhayaal/keystone,rajalokan/keystone,roopali8/keystone,idjaw/keystone,jonnary/keystone,dstanek/keystone,ilay09/keystone,takeshineshiro/keystone,maestro-hybrid-cloud/keystone,vivekdhayaal/keystone,jamielennox/keystone,openstack/keystone,ilay09/keystone,klmitch/keystone,himanshu-setia/keystone,rajalokan/keystone,dstanek/keystone,ajayaa/keystone,idjaw/keystone,jamielennox/keystone,dstanek/keystone,openstack/keystone,jonnary/keystone,roopali8/keystone,cernops/keystone,cernops/keystone