Fix type warning in the panel (on Kirby 3.8.3)

Author: Daandelange

blueprints/tabs/page.php

@@ -43,7 +43,7 @@
 
     if (sizeof($sections) > 0) {
         $columns['meta_sidebar'] = [
-            'sticky' => 'true',
+            'sticky' => true,
             'width' => '1/3',
             'sections' => $sections,
         ];