Authentication plugins have settings link even when they don't have any settings (i.e. No login, LTI, WS)

Steps to reproduce:

1. Go to Site administration ► Plugins ► Authentication ► Manage authentication
2. Enable LTI authentication plugin.
3. Click on Settings link next to LTI plugin
4. You will observe that it has no form and just Save changes button.

It would be nice not to have Settings link, if there is no setting to set for authentication plugin.

Same situation for other auth plugins that have no settings - No login, web services authentication, etc.