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.

--% conflicts: mod_bookmarks
module:log("info", "mod_bookmarks has been deprecated, now loading mod_bookmarks2")
module:depends("bookmarks2")