Fix cleanup for networking quota

With the introduction of changes in [1], the tempest tests
for "neutron quota" needs to be changed. This is because,
unlike earlier, if the a tenant does not have a user-defined
quota, calling "neutron quota-delete" on that tenant will now
return 404.

[1]:https://review.openstack.org/#/c/276096/
Needed-By: I1cd91b5e06bd17f9aac97bba71228f2e5c48879b

Change-Id: I92655bd6358aabc149c8f8d279bd0ce9bc66fe64
1 file changed