neutron: remove redundant request.network_id assignment
neutron: remove redundant request.network_id assignment

Earlier in this loop we're checking the requested network IDs
against the available networks and when we find a match we
move on, if we don't find a match we skip that requested network.

For whatever reason, probably refactors over time, we were setting
the request.network_id to the network['id'] value but we set the
network variable from the net variable whose id matched the
request.network_id, so they are the same.

Anyway, remove this code since it's redundant and confusing.

Change-Id: I33755c81539238e68e0f559477fc137c68fdc6cb

NeCTAR-RC/nova,cloudbase/nova,gooddata/openstack-nova,vmturbo/nova,cloudbase/nova,klmitch/nova,hanlind/nova,mahak/nova,gooddata/openstack-nova,mikalstill/nova,cernops/nova,zhimin711/nova,hanlind/nova,jianghuaw/nova,cyx1231st/nova,vmturbo/nova,sebrandon1/nova,phenoxim/nova,gooddata/openstack-nova,Juniper/nova,rajalokan/nova,rajalokan/nova,CEG-FYP-OpenStack/scheduler,Juniper/nova,bigswitch/nova,Juniper/nova,Juniper/nova,sebrandon1/nova,hanlind/nova,klmitch/nova,openstack/nova,cloudbase/nova,openstack/nova,mikalstill/nova,CEG-FYP-OpenStack/scheduler,klmitch/nova,BeyondTheClouds/nova,BeyondTheClouds/nova,jianghuaw/nova,gooddata/openstack-nova,rajalokan/nova,mahak/nova,alaski/nova,vmturbo/nova,rahulunair/nova,NeCTAR-RC/nova,alaski/nova,rahulunair/nova,jianghuaw/nova,rajalokan/nova,cernops/nova,bigswitch/nova,klmitch/nova,openstack/nova,BeyondTheClouds/nova,rahulunair/nova,mahak/nova,phenoxim/nova,jianghuaw/nova,cernops/nova,cyx1231st/nova,vmturbo/nova,zhimin711/nova,mikalstill/nova,sebrandon1/nova