Remove feed name from 'Access Denied' message while importing feeds

When importing a feed .zip file, the user can select a category to import it into. If the user does not have access to create feeds under that category an exception is displayed in UI:

Access Denied. You do not have access to create feeds under the category cat01.feed06.

For example, in the above message, the category is cat01. The feed06 portion should be removed from the message.