LSO: include check if lso abstract or extro image exists. If not do n…

…ot execute deletion of file(s). (#37590) (ILIAS-eLearning#6234)

Modules/LearningSequence/classes/Settings/class.ilLearningSequenceFilesystem.php

@@ -1,7 +1,5 @@
 <?php
 
-declare(strict_types=1);
-
 /**
  * This file is part of ILIAS, a powerful learning management system
  * published by ILIAS open source e-Learning e.V.
@@ -18,6 +16,8 @@
  *
  *********************************************************************/
 
+declare(strict_types=1);
+
 /**
  * Storage of images in settings.
  */
@@ -69,7 +69,9 @@ public function delete_image(string $which, ilLearningSequenceSettings $settings
             $delete = $settings->getExtroImage();
             $settings = $settings->withExtroImage();
         }
-        $this->deleteFile($delete);
+        if (!empty($delete)) {
+            $this->deleteFile($delete);
+        }
         return $settings;
     }