gate_hook: Remove a stale comment
gate_hook: Remove a stale comment

I believe the bug has been fixed.

Related-Bug: #1583214
Change-Id: I8ec819858c0235f657aff8c7233eb82548e7d737

huntxu/neutron,noironetworks/neutron,openstack/neutron,eayunstack/neutron,mahak/neutron,openstack/neutron,eayunstack/neutron,mahak/neutron,mahak/neutron,openstack/neutron,noironetworks/neutron,huntxu/neutron