Let bureaucrats add users to accountcreator on elwiki

This patch enables users in the 'bureaucrat' user group
on elwiki (Greek Wikipedia) to add and remove other
users from the 'accountcreator' user group.

See bug for URL with on-wiki consensus for this change.

Bug: 59997
Change-Id: Ic2222a714ceb332035695f8f2f57b64f7df24d98