Remove non-voting documentation gate job
Remove non-voting documentation gate job

The checkniceness job is non-voting and thus doesn't need to run
as part of the gate, running it at check time is enough.

Change-Id: I98683cd6e185fc891401135ae446f66a46f2f720

coolsvap/project-config,citrix-openstack/project-config,anbangr/osci-project-config,Tesora/tesora-project-config,citrix-openstack/project-config,open-switch/infra_project-config,openstack-infra/project-config,noorul/os-project-config,noorul/os-project-config,osrg/project-config,coolsvap/project-config,open-switch/infra_project-config,openstack-infra/project-config,Tesora/tesora-project-config,dongwenjuan/project-config,osrg/project-config,anbangr/osci-project-config,dongwenjuan/project-config