In Nova cells v1 has been deprecated since Ocata but we
have no notices about it. This adds warnings about it
being deprecated and will be removed.
The functionality in nova::cells when passing create_cells
parameter is broken and has therefore been removed and
instead outputs a warning and is deprecated.
A known issue has been added to the release notes to inform
about this. It's probably safe to say that nobody is using it
since it has been broken since we switched over to transport_url
for rabbit, it's also safe to probably assume that no deployments
that run cell v1 right now will be running a later version of Nova.
Closes-Bug: 1687395
Change-Id: I564fc4f43a752b051280dce095a52ca4d477fb09