mod_http_oauth2: Reference grant by id instead of value Fixes that the grant got mutated on use of refresh token, notably it would gain 'id' and 'jid' properties set there by mod_tokenauth. Previously also the secret token that we should not be remembering.

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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`.