Cannot edit global group from subwiki administration

Reproducing steps:

• Create a new group "NewGroup"
• Create a subwiki open to both local and global members
• In the subwiki Administration > Group, display the global groups, and edit "NewGroup"

Expected result:

• the modal for editing groups is displayed and allow to add users in the group

Obtained result:

• an empty modal is displayed

Apparently the request for the modal does not take into account if the group is local or global:

http://localhost:8080/xwiki/wiki/subwiki/edit/XWiki/NewGroup?xpage=plain