Fix test which checks removing of user

The name of delete action is now 'delete_active_user' not just 'delete' therefore
tests needs to be fixed.

https://fedorahosted.org/freeipa/ticket/6052

Reviewed-By: Lenka Doudova <ldoudova@redhat.com>

ipatests/test_webui/test_user.py

@@ -161,7 +161,7 @@ class test_user(UI_driver):
         self.action_list_action('unlock')
 
         # delete
-        self.delete_action(user.ENTITY, user.PKEY)
+        self.delete_action(user.ENTITY, user.PKEY, action='delete_active_user')
 
     @screenshot
     def test_password_expiration_notification(self):