changeset.set('nested.path', undefined) does not update property

[kdagnan]

Version: 4.1.2

Example:

changeset.set('nested.path', true); 
changeset.get('nested.path') // true

changeset.set('nested.path', undefined);
changeset.get('nested.path') // true

Possibly related to: https://github.com/adopted-ember-addons/ember-changeset/pull/191