by iflylabs: user picture bug fix

src/Controller/drupalchatController.php

@@ -741,7 +741,7 @@ class drupalchatController extends ControllerBase {
       '#account' => $u,
     );
   
-    if ((null !== $u->user_picture->first()) && is_object($u->user_picture->first())) {
+    if ((!empty($u->user_picture)) && (null !== $u->user_picture->first()) && (is_object($u->user_picture->first()))) {
       $renderImage = $u->user_picture->first()->view('large');
       $user_image = \Drupal::service('renderer')->renderPlain($renderImage);
       $user_image = print_r($user_image, true);//(string)$row_user;