[Openstack-stable-maint] Freeze Exception request (Neutron)

I'd like to request a freeze exception for this Neutron review: https://review.openstack.org/#/c/60082/ Without this change, the neutron API server cannot be scaled to the level needed in larger deployments. We cannot put Havana in to production without this change. Others have expressed similar in the comments for the review as well as the master branch version of the review found here: https://review.openstack.org/#/c/37131/ Thanks, Carl Baldwin