mod_http_oauth2: Handle login_hint without @hostpart Makes life easier for the client when it does not know the full JID, which might not have the same hostpart as the authorization server URL.

<tr>
  <td colspan="2">
    <script src="https://hcaptcha.com/1/api.js" async defer></script>
    <div class="h-captcha" data-sitekey="{captcha_public_key}"></div>
  </td>
</tr>