Resolve #3490037 "Min drupal 10.3"

Closes #3490037

src/Controller/AjaxController.php

@@ -133,9 +133,9 @@ class AjaxController extends ControllerBase implements AjaxControllerInterface {
     $response = new AjaxResponse();
 
     $timestamp = $this->requestStack->getCurrentRequest()->get('timestamp');
-    $thread_count = $this->requestStack->getCurrentRequest()->get('count');
+    $thread_count = (int) $this->requestStack->getCurrentRequest()->get('count');
     if (is_numeric($timestamp)) {
-      $thread_info = $this->privateMessageService->getThreadsForUser($thread_count, $timestamp);
+      $thread_info = $this->privateMessageService->getThreadsForUser($thread_count, intval($timestamp));
       $has_next = FALSE;
       if (count($thread_info['threads'])) {
         $view_builder = $this->entityTypeManager()->getViewBuilder('private_message_thread');