mod_smacks: Fix traceback due to session being destroyed in send() Sending something can cause the OS to notice that the connection is dead and then the connection can be dead at this point. More likely if opportunistic_writes is enabled.

<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>