Removed some CSS rules as the toolbar can now be configured through the settings

As the toolbar can now be configured through the settings.json file, these custom CSS rules can be removed
This is a regression in etherpad 1.4.0. It's been fixed in their current `develop` branch in https://github.com/ether/etherpad-lite/commit/46ef83d7106c1a94c9db161203f4df7b2773cbf4. If you want, we can deploy a custom release that includes the fix. Or we can try to include the fix in `ep_oae`