Change image to glyphicon for status captive portal

src/www/status_captiveportal.php

@@ -200,7 +200,7 @@ $mac_man = load_mac_manufacturer_table();
 								    <td class="listr" colspan="2"></td>
 									<?php endif; ?>
 								    <td valign="middle" class="list nowrap">
-								      <a href="?zone=<?=$cpzone;?>&amp;order=<?=$_GET['order'];?>&amp;showact=<?=htmlspecialchars($_GET['showact']);?>&amp;act=del&amp;id=<?=$cpent->sessionid;?>" onclick="return confirm('<?=gettext("Do you really want to disconnect this client?");?>')"><img src="./themes/<?= $g['theme']; ?>/images/icons/icon_x.gif" width="17" height="17" border="0" title="<?=gettext("Disconnect");?>"></a>
+								      <a class="btn btn-default btn-xs" href="?zone=<?=$cpzone;?>&amp;order=<?=$_GET['order'];?>&amp;showact=<?=htmlspecialchars($_GET['showact']);?>&amp;act=del&amp;id=<?=$cpent->sessionid;?>" onclick="return confirm('<?=gettext("Do you really want to disconnect this client?");?>')" title="<?=gettext("Disconnect");?>"><span class="glyphicon glyphicon-remove"></span></a>
 								    </td>
 								  </tr>
 								<?php endforeach; endif; ?>