fix typo

src/PermissionsHook.php

@@ -130,7 +130,7 @@ class PermissionsHook implements
 
         // Add Add Log
         $oldGroups = $this->userGroupManager->getUserGroups($user); // previous groups
-        $newGroups = array_merge($oldGroups, [$added_group]); // all groups
+        $newGroups = array_merge($oldGroups, [$added_group]); // new groups
         $logEntry = new ManualLogEntry('rights', 'autopromote');
         $logEntry->setPerformer($user);
         $logEntry->setTarget($user->getUserPage());
@@ -155,11 +155,7 @@ class PermissionsHook implements
 
         // Add Remove Log
         $oldGroups = $this->userGroupManager->getUserGroups($user); // previous groups
-        $newGroups = [...$oldGroups]; // all groups
-        $key = array_search($removed_group, $newGroups);
-        if ($key !== false) {
-            array_splice($newGroups, $key, 1);
-        }
+        $newGroups = array_intersect($oldGroups, [$removed_group]); // new groups
         if ($oldGroups !== $newGroups) {
             $logEntry = new ManualLogEntry('rights', 'autopromote');
             $logEntry->setPerformer($user);