FIX: Group owners should be able to invite users to their groups.

https://meta.discourse.org/t/group-owner-cannot-send-an-invite-to-a-group/60617/12

app/controllers/admin/groups_controller.rb

@@ -1,19 +1,4 @@
 class Admin::GroupsController < Admin::AdminController
-
-  def index
-    groups = Group.order(:name).where("groups.id <> ?", Group::AUTO_GROUPS[:everyone])
-
-    if search = params[:search].to_s
-      groups = groups.where("name ILIKE ?", "%#{search}%")
-    end
-
-    if params[:ignore_automatic].to_s == "true"
-      groups = groups.where(automatic: false)
-    end
-
-    render_serialized(groups, BasicGroupSerializer)
-  end
-
   def show
     render nothing: true
   end