Show "Not found" page if user lacks permission for entity. #4139
Motivation and Context
Before this change, the user was redirected to the user's startpage,
With this change, the user is redirected to the already existing "Not
This change should also be merged into
How Has This Been Tested?
Screenshots (if appropriate):
Types of changes
Before this change, the user was redirected to the user's startpage, when fetching an entity failed with an http error code of 403 (obviously being the case for non-admin users only, admin users either get the entity or a 404). This results in an infinite redirect loop if the missing or non-permitted entity/resource is the same as the configured start page. With this change, the user is redirected to the already existing "Not found" page previously used to handle nonexisting resources. This also raises the user's attention that the configured start page is inaccessible. Fixes #4117.