fix: use new method for setting client id

[rgraber]

Use the new method in openedx-events instead of accessing the settings directly

Merge checklist: Check off if complete or not applicable:

• [ ] Version bumped
• [ ] Changelog record added
• [ ] Documentation updated (not only docstrings)
• [ ] Commits are squashed
• [ ] Noted any: Concerns, dependencies, deadlines, tickets, testing instructions