Updated openstack/openstack
Project: openstack/nova  f0f35f04561ef00bf09528c6d3b82e7ce932de89

Remove outdated docstring for nova.network.manager

There was related-flags section to describe config options, but was
outdated and duplicated with config options' description in code.
So We should remove it.

Change-Id: Ie0e444810393c77f04c1adbafdeb83c99d970902