trivial: Cleanup Sphinx config file, setup.cfg
trivial: Cleanup Sphinx config file, setup.cfg

Remove unused noise from the former and unused Sphinx configuration from
the latter.

Change-Id: I754f02fd6eb3c1d77ff2580d53685f4a70da8cc6
Signed-off-by: Stephen Finucane <4725dc7f3632bf126d9fbdc30c347e91e8d2fe16@redhat.com>

openstack/oslo.privsep