Remove grenade linuxbridge multinode job from neutron dashboard
Remove grenade linuxbridge multinode job from neutron dashboard

The job was moved to experimental, so now it's not consistently
triggered, and so keeping it on the dashboard is of no value.

Change-Id: I9f62ee6794c48367d4f8bf0a69914c6dfe0fff40

openstack-infra/project-config,openstack-infra/project-config