Project milestones should be ordered by due_date like global milestones?

I think this issue is related with #1125 (closed) and !1934 (merged).

and it will be fixed by making changes like following.

app/controllers/projects/milestones_controller.rb

  def index
    @milestones = case params[:state]
-                  when 'all'; @project.milestones.order("state, due_date DESC")
-                  when 'closed'; @project.milestones.closed.order("due_date DESC")
-                  else @project.milestones.active.order("due_date ASC")
+                  when 'all'; @project.milestones.reorder("state, due_date DESC")
+                  when 'closed'; @project.milestones.closed.reorder("due_date DESC")
+                  else @project.milestones.active.reorder("due_date ASC")
                  end

    @milestones = @milestones.includes(:project)
    @milestones = @milestones.page(params[:page]).per(PER_PAGE)
  end