The neutron-debug command was deprecated and finally removed,
so tools/ping_neutron.sh can no longer rely on it to create
a probe namespace. Instead, just try and use any namespace
with the network ID in it, since it's either the DHCP (ML2/OVS)
or Metadata (OVN) namespace, which should work just as well.
As this code is rarely (never?) used, this best-effort attempt
is good enough.
Change-Id: I98c992a2a774ef1fb22cee2e90ee342ab2d537ac
Depends-on: https://review.opendev.org/c/openstack/neutron/+/883081
6764eab264