Impersonating blocked user logs you off

Created by: Baertierchen

When trying to impersonate a user that is currently blocked, you end up being logged off. After logging back in with your own credentials, the button to stop impersonation appears even though you are logged in as yourself at this time. Would be nicer if you were simply told that you can't impersonate blocked users and remain logged in. That's on 8.2.1 tag.