No check for ports in subnet on openstack before deleting it from Nuage VSD

[Prinika]

Steps to recreate:

1. Create a net + subnet
neutron net-create n
neutron subnet-create n 10.10.10.0/24 --name n

2. Create a port
neutron port-create --fixed-ip subnet_id=n --name port1 n

3. Delete the subnet n.
This gives the following error on openstack and does not delete the subnet on openstack but deletes it from the Nuage VSD
 (Unable to complete operation on subnet <UUID>. One or more ports have an IP allocation from this subnet)

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/113003

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/113003
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=949c29ec7fbe965483484c4192ca960bece1802a
Submitter: Jenkins
Branch: master

commit 949c29ec7fbe965483484c4192ca960bece1802a
Author: ronak <email address hidden>
Date: Fri Aug 8 12:13:16 2014 -0700

    Check for ports in subnet before deleting it from Nuage VSD

    There could exist a port in subnet in neutron in which case subnet delete
    is not allowed. In the nuage's plugin code, this validation needs to
    be handle prior to sending delete subnet request to backend.

    Change-Id: Idd20d2f878a6274a012504108d01bd2237dc665a
    Closes-bug: #1351522