Release v19.24.1

Fixed

• An event whose constrained properties are all null or missing no longer claims the empty-string value in a unique constraint, so a later event from another source holding "" is no longer rejected as a violation. Clearing a constrained value now frees the claim the source held, so another source can then claim it. (#4383)
• Observers.MaxConcurrentPartitions is now documented as what it is, an upper bound on parallel job steps applied together with Jobs.MaxParallelSteps, not a limit on live event delivery. The setting is added to the configuration reference. (#4405)