Neutronv2 api does not support neutron without port quota

If quota on ports are disabled in neutron (see below), neutronv2 api
set port quota to None and quota check raises a TypeError.

  # neutron server /etc/neutron/neutron.conf
  [quotas]
  quota_items=network,subnet,router,floatingip

This change set port quota to -1 (unlimited) if quota on ports are
disabled.

Change-Id: I89c530dd57a7beb35695be124ca8511148378458
Closes-Bug: #1333315
(cherry picked from commit 04add2ed0d8b0341ea347ac98834f75cf5b2be1d)
Merge "Neutronv2 api does not support neutron without port quota" into stable/icehouse