AMv3 Status bugfix
Occasionally, geni_ready was returned as reply to an AMv3 Status call, while the sliver was not at all ready yet. (This issue does not occur in AMv2.)
That's bad for clients like jFed, which then stop periodically calling Status, and report to the user that everything is ready.
The cause was a bad fallback AMv3 status in case of an unknown internal status (geni_ready was the fallback). This fix just returns "unknown" in that case, which fixes the problem. (Because the "unknown" status seems to be only intermediary anyway.)