mod_http_oauth2: Declare additional client registration fields as strings Previously any property not listed in the schema was allowed in any form, which is probably a bit too liberal. Instead, limit extra fields to simple strings, which should still allow localized versions of the various URIs and descriptive properties per RFC 7591 §2.2

---
summary: Store registration events in the audit log
rockspec:
  dependencies:
  - mod_audit
...

This module stores successful user registrations in the audit log provided by
`mod_audit`.