Disable lbaas from odl-neutron-driver

odl-neutron-driver's lbaas no longer works, due to new split neutron services repos
See: https://github.com/openstack-dev/devstack/commit/20b839fd51ff0ccecbc67f3d29578ce042c8b3c3

Since this repo is folding into stackforge, there is no point in addressing this now.