Remove redundant constrain from constant runner schema
Remove redundant constrain from constant runner schema

Change-Id: I720c48b4761805606572693f88e5227617738640

vganapath/rally,vganapath/rally,eayunstack/rally,yeming233/rally,vganapath/rally,yeming233/rally,openstack/rally,gluke77/rally,openstack/rally,eayunstack/rally,vganapath/rally,openstack/rally,openstack/rally,gluke77/rally,gluke77/rally,eonpatapon/rally,gluke77/rally,eayunstack/rally,eonpatapon/rally