mod_http_admin_api: Tweak token session to please module:may() module:may() checks for type == "c2s", but mod_tokenauth does not currently include that or most common session properties. Fixes a traceback resulting from a different code path where module:may() tries to index event.stanza, which does not exist for http events.

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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`.