Steps to reproduce:

1. Open any user role for editing.
2. Cut the name (leave the field empty).
3. Click the Update button.
4. Observe:
   1. The form reloads with error:
      Cannot update user role: Incorrect value for field "name": cannot be empty.
   2. Also, the Add button is displayed instead of the Update button below the form.
5. Put the name back.
6. Click the Add button.
7. Observe:
   1. The form reloads with error:
      Cannot create user role: User role "..." already exists.

Expected:

On errors, still editing the existing user role and not creating a new one.