Remove index renames in GeneralizeWikiMenuItems

Commented in 8078f73c.

Index renames are no longer needed in Rails 4.0:

> In Rails 4.0 when a column or a table is renamed the related indexes
> are also renamed. If you have migrations which rename the indexes,
> they are no longer needed.

See: http://guides.rubyonrails.org/upgrading_ruby_on_rails.html

[ci skip]

Signed-off-by: Alex Coles <alex@alexbcoles.com>

db/migrate/20131004141959_generalize_wiki_menu_items.rb

@@ -32,21 +32,15 @@ class GeneralizeWikiMenuItems < ActiveRecord::Migration
     rename_table :wiki_menu_items, :menu_items
     add_column :menu_items, :type, :string
     rename_column :menu_items, :wiki_id, :navigatable_id
-    # rename_index :menu_items, 'index_wiki_menu_items_on_parent_id', 'index_menu_items_on_parent_id'
-    # rename_index :menu_items, 'index_wiki_menu_items_on_wiki_id_and_title', 'index_menu_items_on_navigatable_id_and_title'
 
     MenuItem.find_each do |menu_item|
       menu_item.update_attribute :type, 'MenuItems::WikiMenuItem'
     end
-
-    # TODO rename indexes
   end
 
   def down
     rename_table :menu_items, :wiki_menu_items
     remove_column :wiki_menu_items, :type
     rename_column :wiki_menu_items, :navigatable_id, :wiki_id
-    # rename_index :wiki_menu_items, 'index_menu_items_on_parent_id', 'index_wiki_menu_items_on_parent_id'
-    # rename_index :wiki_menu_items, 'index_menu_items_on_navigatable_id_and_title', 'index_wiki_menu_items_on_wiki_id_and_title'
   end
 end