Use /etc/neutron/neutron.conf

Use /etc/neutron/neutron.conf for configuration, not
/usr/share/neutron/neutron-dist.conf. The latter is intended for
distributors to provide their recommended settings/overrides but these
are overridden by whatever is in /etc/neutron/neutron.conf.

Change-Id: I4c6037140e969865a47de7873cd985286c8ec13a
Closes-Bug: #1284098