Wrong right resolution when denying a right to user who belongs to group with PR

Reproduction steps:

• Create a group with PR right (or use XWikiAdminGroup from default flavor)
• Create a user and put it in that group
• Deny the delete right to that user

Expected result:

• Since the user belongs to a group with PR right, they should still be able to delete pages

Obtained result:

• The user is not able anymore to perform delete actions

Note that if the PR right is given explicitely to the user then they can still delete pages.