Issue #3486192 by grimreaper: Fix menu local tasks active state

src/HookHandler/PreprocessMenuLocalTasks.php

@@ -45,8 +45,10 @@ class PreprocessMenuLocalTasks {
 
         if ($menuLocalTask['#active']) {
           $menuLocalTask['#link']['url']->mergeOptions([
-            'class' => [
-              'active',
+            'attributes' => [
+              'class' => [
+                'active',
+              ],
             ],
           ]);
         }