Release v19.77.1

After a namespace was removed, any client that still had it open registered everything in it again the next time the kernel restarted and the client reconnected, which created the namespace, its observers and its databases again - empty. Found removing a test organization from production: the removal completed, then the namespace returned when Chronicle was rolled.

Fixed

• An event store of a namespace other than the default one asks the kernel whether the namespace still exists when it reconnects. If the kernel no longer lists it, the event store lets go of it instead of registering, and the client creates a new one if the namespace is used again. If the kernel cannot be asked, it registers as before (#4942).