set keystone's legacy_drivers job to voting
set keystone's legacy_drivers job to voting

this has been non-voting for a while and should be voting. it has
caught a handful of valid errors and failed, and suceeded for all
other patches.

Change-Id: I9266435595f4e7b4c1416fb8f0c5257b220dfeb6

openstack-infra/project-config,openstack-infra/project-config,Tesora/tesora-project-config,Tesora/tesora-project-config,dongwenjuan/project-config,noorul/os-project-config,noorul/os-project-config,dongwenjuan/project-config