Horizon revokes admin role from user if cannot get user_list

[Paul Karikh]

1) Deploy Horizon with users storing in LDAP
2) Create a lot of users in LDAP so Keystone couldn't return user_list
3) Go to identity/projects and try to update quotas for project where you have admin role

Sometimes you get message 'You cannot revoke your administrative privileges from the project you are currently logged into.' and sometimes you will lose your admin role.

MOS 7.0