Fix migration bug

lib/tasks/migrate.rake

@@ -362,7 +362,7 @@ namespace :migrate do
     i = 1
     news_bulletins.each do |news|
       p "#{i}/#{news_bulletins.size} - #{news.id}"
-      news.subtitle.gsub!(/^\<p\>/, '').gsub!(/\<\/p\>$/, '') rescue nil
+      news.subtitle_translations = {'en' => (news.subtitle_translations['en'].gsub(/^\<p\>/, '').gsub(/\<\/p\>$/, '') rescue ''), 'zh_tw' => (news.subtitle_translations['zh_tw'].gsub(/^\<p\>/, '').gsub(/\<\/p\>$/, '') rescue nil)}
       p news.save(:validate => false) if news.changed?
       i += 1
     end if news_bulletins