mate-user-admin,group-service: add mate-user-admin and dependency
This MR is companion of !1227 (merged) and trisquel-packages!107 (merged) in order to include mate-user-admin on T11, while T12 gets these fixes by default.
This MR is companion of !1227 (merged) and trisquel-packages!107 (merged) in order to include mate-user-admin on T11, while T12 gets these fixes by default.