When deleting a "No limitation" Role that has been added after other (with limitations), the assignment is not cleared completely - previous limitations are displayed.

Steps to reproduce:
1. Go to Admin/Roles
2. Create new Role
3. Go to Assignments and choose "Assign users/groups"
4. Select a user and "Sections" limitations: Standard, Users
5. Save
6. Add the same user to the Role, this time without Limitation (No limitation option)

Result so far:
Only the user with "No limitation" row is displayed in the Assignments list

7. Remove the displayed assignment

Expected:
There are no assignments for the Role

Actual:
The assignments added before (Standard, Users sections) are visible.