UserGroupForm: Fix redirect when renaming a group

refs #8826

application/forms/Config/UserGroupForm.php

@@ -33,6 +33,24 @@ class UserGroupForm extends RepositoryForm
         }
     }
 
+    /**
+     * Update a group
+     *
+     * @return  bool
+     */
+    protected function onUpdateSuccess()
+    {
+        if (parent::onUpdateSuccess()) {
+            if (($newName = $this->getValue('group_name')) !== $this->getIdentifier()) {
+                $this->getRedirectUrl()->setParam('group', $newName);
+            }
+
+            return true;
+        }
+
+        return false;
+    }
+
     /**
      * Create and add elements to this form to delete a group
      *