Updated openstack/openstack
Project: openstack/oslo.config  83236b0d7dbdbaa5c2ebe73925ee0f1928d16aff

Explain groups for DeprecatedOpts

The patch extends the documentation for `DeprecatedOpt` and explains
that group==None means the deprecated name will be looked up in the same
group.

Change-Id: I54ba414d6a6862e1b00dfbf589563ef9f4df5cf3