Gitea sends `requested_reviewer` (singular) field for `review_requested`
webhook actions, not always the `requested_reviewers` (plural/array).
The processor only checked the array form, so `usersToNotify` was always
empty and no notification was sent.
Also add more INFO-level logging for debugging the review_requested path.
Fixes: manual mappings worked but were never reached because the
processor never added the reviewer to the notification list.
JimKarvo
895b82096c