Description of problem:
Add a Role to a Privilege - say - IT Security Specialist.
This is listed in lower case when viewing this privilege. Click to Add another
Role, and IT Security Specialist is still listed (this is inconsistent with
other Add member dialogs, where already added members are not listed).
But if helpdesk was the Role added, this behaviour is not seen, since the Role
is in lowercase, and is recognized to be as added Role.

Version-Release number of selected component (if applicable):
ipa-server-2.2.0-16.el6.x86_64

How reproducible:
always

Steps to Reproduce:
1. Add a Role to a Privilege - say - IT Security Specialist.
2. Clock to Add another Role

Actual results:
IT Security Specialist is still listed

Expected results:
IT Security Specialist should not be listed.

Additional info:
If IT Security Specialist is chosen to be added - it will thorw an error as
expected - This entry is already a member