Fix devstack plugin.sh
Fix devstack plugin.sh

Do the copy of config file at the 'config' stage.
(/etc/neutron does not exist yet at the 'install' stage)

Change-Id: I9d98356fa864aada125d87893bfb5c3aeba347eb

openstack/networking-bgpvpn,openstack/networking-bgpvpn,openstack/networking-bgpvpn