Network attach failed beacuse network doesn't has preserve_on_delete field

[chengyang]

Network attach failed beacuse network doesn't has preserve_on_delete field.
In zun/network/kuryr_network.py, latest code of function create_or_update_port will judge value of preserve_on_delete field in requested_network, so we need to update body of requested_network when attach network

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/527344
Committed: https://git.openstack.org/cgit/openstack/zun/commit/?id=76801e9afb9ea46d0626d2567c07c45c187bc983
Submitter: Zuul
Branch: master

commit 76801e9afb9ea46d0626d2567c07c45c187bc983
Author: chengyang <email address hidden>
Date: Tue Dec 12 16:38:18 2017 +0800

    Add preserve_on_delete field in requested_network when attach network

    Attaching a container to a neutron network failed with KeyError
    on retrieving the 'preserve_on_delete' key from the requested
    network. This is because the latest code change in kuryr_network.py
    assumes the 'preserve_on_delete' key is presented but this key is
    missing.

    Change-Id: I3e3a1dc35227d4f469619bb8eb9215ca49b3343f
    Closes-bug: #1737687

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/zun 1.0.0 release.