mod_http_oauth2: Gracefully handle cache write failure Would previously have thrown an error and probably returned a traceback. This would only happen if a *lot* of authorization codes were requested in a short interval.

<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>