remove duplicate method

app/models/article.rb

@@ -51,7 +51,6 @@ def spam
   scope :category, lambda { |category_id| where('categorizations.category_id = ?', category_id).includes('categorizations') }
   scope :drafts, lambda { where(state: 'draft').order('created_at DESC') }
   scope :child_of, lambda { |article_id| where(parent_id: article_id) }
-  scope :published, lambda { where(published: true, published_at: Time.at(0)..Time.now).order('published_at DESC') }
   scope :published_at, lambda {|time_params| published.where(published_at: PublifyTime.delta(*time_params)).order('published_at DESC')}
   scope :published_since, lambda {|time| published.where('published_at > ?', time).order('published_at DESC') }
   scope :withdrawn, lambda { where(state: 'withdrawn').order('published_at DESC') }