Previously the usage of neutron debug ports was removed by
5e01c47e4d671166b9396c507a7105a5ac8256dc but there was still call to
teardown_neutron_debug. Recently a change to devstack-gate
1d6cc0771a3399300117f488e9d71e7ea46a4d82 caused that call to be
triggered and breaking the gate-devstack-dsvm-updown job.
This patch deletes the call and comments regarding setup_neutron_debug
and teardown_neutron_debug.
Change-Id: Ifdacb0cec1307db469bd66f551474539184cf2cd