Annotation Life Stage can not be set if "Juvenile" was set before by another user

[sessilefielder]

It’s a known issue:

• https://forum.inaturalist.org/t/unable-to-add-annotation-to-a-sighting/57569/10
• https://forum.inaturalist.org/t/cannot-annotate-life-stage-when-previous-value-existed/57783