Don't allow users to delete their own account.

- In keystoneauth we allowed authenticated users to delete their own
  account we are disallowing that and only allow users with reseller
  admin to do that for its own or for the others.
- Fixes bug 1177526.

Change-Id: I825c5a968e8eae0991915056825fe0e0c195647e
Merge "Don't allow users to delete their own account."