mod_storage_s3: Enable connection pooling added in latest trunk Speed boost, something like a 30% improvement with http://localhost Small risk of failed requests due to limits on number of requests per connection or timeouts.

<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>