Exclude domains with inherited roles from user domain list.

The list_domains_for_user() method is supposed to only return the
domains for which a user has a role (direct or via a group).
However, it currently ignores the inherited attribute, hence will
incorrectly return domains which only contain inherited roles.

This patch fixes this issue.

Closes-bug 1390640

Change-Id: Iadcafd8e60ff5532d788c865a8cd3b180de31b4f
Merge "Exclude domains with inherited roles from user domain list."