owncloud/core

Change: Remove the "add group" button from the dropdowns in the users page

The "add group" button has been removed from the dropdowns because the
behavior was confusing. You can still create new groups in the users
page by using the "add group" button in the top left corner of the users page.
The dropdowns will only select existing groups, but they won't add new groups.

https://github.com/owncloud/core/pull/40770