fix multiple notifications from being sent for multiple labels
What does this MR do?
Prevent multiple notifications from being sent when multiple label (upon which a user is subscribed) are added to an issue.
Are there points in the code the reviewer needs to double check?
See the changes in the
Why was this MR needed?
Multiple duplicate notification emails are sent when adding N labels upon which a user is subscribed. This is noise in the inbox.
Does this MR meet the acceptance criteria?
- Changelog entry added, if necessary
- Documentation created/updated
- API support added
- Tests added for this feature/bug
- Has been reviewed by UX
- Has been reviewed by Frontend
- Has been reviewed by Backend
- Has been reviewed by Database
- Conform by the merge request performance guides
- Conform by the style guides
- Squashed related commits together