DHCP RPC context exception in NEC plugin

[Akihiro Motoki]

RPC context was changed in https://review.openstack.org/#/c/15726
RPC between DHCP agent and Quatum server raises an exception in NEC plugin.

[-] Exception during message handling
Traceback (most recent call last):
  File "/opt/stack/quantum/quantum/openstack/common/rpc/amqp.py", line 276, in _process_data
    rval = self.proxy.dispatch(ctxt, version, method, **args)
  File "/opt/stack/quantum/quantum/openstack/common/rpc/dispatcher.py", line 133, in dispatch
    return getattr(proxyobj, method)(ctxt, **kwargs)
  File "/opt/stack/quantum/quantum/db/dhcp_rpc_base.py", line 37, in get_active_networks
    plugin.get_networks(context, filters=filters)]
  File "/opt/stack/quantum/quantum/plugins/nec/nec_plugin.py", line 306, in get_networks
    nets = super(NECPluginV2, self).get_networks(context, filters, None)
  File "/opt/stack/quantum/quantum/db/db_base_plugin_v2.py", line 983, in get_networks
    filters=filters, fields=fields)
  File "/opt/stack/quantum/quantum/db/db_base_plugin_v2.py", line 217, in _get_collection
    query = self._get_collection_query(context, model, filters)
  File "/opt/stack/quantum/quantum/db/db_base_plugin_v2.py", line 211, in _get_collection_query
    collection = self._model_query(context, model)
  File "/opt/stack/quantum/quantum/db/db_base_plugin_v2.py", line 90, in _model_query
    query = context.session.query(model)
  File "/opt/stack/quantum/quantum/openstack/common/rpc/common.py", line 331, in __getattr__
    raise AttributeError(key)
AttributeError: session

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/19706

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/19706
Committed: http://github.com/openstack/quantum/commit/53a787d258fe26cfd24578f6c84d28eb4b90648f
Submitter: Jenkins
Branch: master

commit 53a787d258fe26cfd24578f6c84d28eb4b90648f
Author: Akihiro MOTOKI <email address hidden>
Date: Mon Dec 31 05:58:36 2012 +0900

    Catch up RPC context fixes on NEC OpenFlow plugin

    Fixes bug 1099179

    Change-Id: Ib61081c3aaed8770906dd57874c45358b0418c3f