Steps to replicate the issue (include links if applicable):
Create an event on test.wikipedia.org (or meta.wikimedia.org)
Add one private participant
Add one public participant
As an organizer, delete one of the users on Special:EventDetails participant tab
What happens?:
The user does not delete and there is an error:
{"error":"parameter-validation-failed","name":"include_private","value":null,"failureCode":"missingparam","failureData":null,"errorKey":"missingparam","messageTranslations":{"en":"The \"include_private\" parameter must be set."},"httpCode":400,"httpReason":"Bad Request"}
What should have happened instead?:
Participant should be deleted by organizer
Software version (on Special:Version page; skip for WMF-hosted wikis like Wikipedia):
1.43.0-wmf.21 (b7b9c62)
Other information (browser name/version, screenshots, etc.):
Chrome
