Effective Permissions no longer displays users whose permissions are via membership in a group

From Version 5.6, users no longer listed in the Effective Permissions tab if they grant the permissions to the repo by membership in a group (and not directly for the user).

To reproduce (on 5.6 and above):
1. Create a user and a group
2. Assign the user to the group
3. Create a permission target and give the group some permissions
4. Click on the repo in "Artifact Repository Browser" and go to the "Effective Permissions" tab
The bug:
Under "Users", you will not see the created user, but only its group under "Groups".

This is a regression since before 5.6 (access) it works differently, users are listed in this section even if their permissions is only via their group