Cannot configure rights for the members of a subwiki until the first member is added to the wiki

Steps to reproduce are
1/ create subwiki (with no member)
2/ go to rights -> local XWikiAllGroup is not there in the list
3/ go to users, Add a user manually
4/ go to rights- > magically, XWikiAllGroup local is there, and has some rights configured

This is problematic because a local admin cannot configure his wiki fully (rights for members, etc) before members come to his wiki.

Actually, he could, with a hack (adding a member and re-removing it) but it's not nice.

It is because XWikiAllGroup have been removed in 6.2.
It has been removed for a bad reason: not giving conflict when DW is launched (see XWIKI-9813).

The removal is not needed anymore since we are going to have a new wiki creation module that perform the UI installation: XWIKI-10043.