mod_http_oauth2: Strip unknown client metadata Per RFC 7591 > The authorization server MUST ignore any client metadata sent by the > client that it does not understand (for instance, by silently removing > unknown metadata from the client's registration record during > processing). This was previously done but unintentionally removed in 90449babaa48

<tr>
  <th>What is {x} {op} {y}?</th><td>
    <input name="captcha_challenge" type="hidden" value="{challenge}">
    <input name="captcha_reply" pattern="[0-9]+" required type="number">
  </td></tr>