refs #17834 [VuFind-Core] fixes casting error in uptime display

* this is fixed in VF6

themes/bootstrap3/templates/admin/home.phtml

@@ -34,7 +34,7 @@
       <tr>
         <th><?=$this->transEsc('Uptime')?>: </th>
         <?php $uptime = $core->xpath('//lst[@name="' . $coreName . '"]/long[@name="uptime"]') ?>
-        <td><?=$this->printms((string)array_pop($uptime))?></td>
+        <td><?=$this->printms((int)array_pop($uptime))?></td>
       </tr>
     </table>
   <?php endforeach; ?>