Acl: Fix broken test due to invalid return value in Auth::user()

This issue became apparent after a recent commit in
cakephp/cakephp@82d57fb8b2d194b0bfdbbe6ecb7e974615c9cc7b
Acl: Fix duplicate values returned by getAllowedActionsByUserId()
Acl: Fix warnings displayed due to invalid aros_acos

Closes #386