Fix update usergroup + format code

public/main/inc/lib/add_course.lib.inc.php

@@ -760,7 +760,6 @@ class AddCourse
                 ->setVisibility($visibility)
                 ->setShowScore(1)
                 ->setDiskQuota($disk_quota)
-                ->setCreationDate(new \DateTime())
                 ->setExpirationDate(new \DateTime($expiration_date))
                 ->setDepartmentName($department_name)
                 ->setDepartmentUrl($department_url)

public/main/inc/lib/usergroup.lib.php

@@ -1825,7 +1825,7 @@ class UserGroup extends Model
         );
 
         $repo = Container::getIllustrationRepository();
-        if ($repo->hasIllustration($userGroup)) {
+        if ($userGroup && $repo->hasIllustration($userGroup)) {
             $picture = $repo->getIllustrationUrl($userGroup);
             $img = '<img src="'.$picture.'" />';
             $form->addElement('label', null, $img);

src/CoreBundle/Repository/Node/IllustrationRepository.php

@@ -127,9 +127,9 @@ final class IllustrationRepository extends ResourceRepository implements GridInt
 
     public function hasIllustration(ResourceIllustrationInterface $resource): bool
     {
-        $illustration = $this->getIllustrationUrlFromNode($resource->getResourceNode());
+        $node = $this->getIllustrationNodeFromParent($resource->getResourceNode());
 
-        return null !== $illustration;
+        return null !== $node;
     }
 
     /**