reverted post version tag change for danbooru2

db/development_structure.sql

@@ -2142,8 +2142,7 @@ CREATE TABLE post_versions (
     created_at timestamp without time zone,
     updated_at timestamp without time zone,
     post_id integer NOT NULL,
-    add_tags text DEFAULT ''::text NOT NULL,
-    del_tags text DEFAULT ''::text NOT NULL,
+    tags text DEFAULT ''::text NOT NULL,
     rating character(1),
     parent_id integer,
     source text,

db/migrate/20100205163027_create_post_versions.rb

@@ -4,8 +4,7 @@ class CreatePostVersions < ActiveRecord::Migration
       t.timestamps
       
       t.column :post_id, :integer, :null => false
-      t.column :add_tags, :text, :null => false, :default => ""
-      t.column :del_tags, :text, :null => false, :default => ""
+      t.column :tags, :text, :null => false, :default => ""
       t.column :rating, :char
       t.column :parent_id, :integer
       t.column :source, :text