reconcile should not overwrite unblocking state (#8349)
reconcile should not overwrite unblocking state (#8349)

Pre-0.12.0 beta, a deployment was considered "complete" if it was
successful. But with MRD we have "blocked" and "unblocking" states as well. We
did not consider the case where a concurrent alloc health status update
triggers a `Compute` call on a deployment that's moved from "blocked" to
"unblocking" (it's a small window), which caused an extra pass thru the
`nextRegion` logic in `deploymentwatcher` and triggered an error when later
transitioning to "successful".

This changeset makes sure we don't overwrite that status.
burdandrei/nomad,dvusboy/nomad,burdandrei/nomad,burdandrei/nomad,dvusboy/nomad,dvusboy/nomad,hashicorp/nomad,dvusboy/nomad,dvusboy/nomad,hashicorp/nomad,burdandrei/nomad,hashicorp/nomad,hashicorp/nomad,dvusboy/nomad,hashicorp/nomad,burdandrei/nomad,dvusboy/nomad,burdandrei/nomad,burdandrei/nomad,hashicorp/nomad