Revert r6104 "Merged r6098 from trunk."

I messed things up with a cherry-pick on master, I'll re-apply it after.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/branches/1.2-stable@6105 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/attachment.rb

@@ -43,7 +43,7 @@ class Attachment < ActiveRecord::Base
                                                         "LEFT JOIN #{Project.table_name} ON #{Document.table_name}.project_id = #{Project.table_name}.id"}
 
   cattr_accessor :storage_path
-  @@storage_path = Redmine::Configuration['attachments_storage_path'] || "#{Rails.root}/files"
+  @@storage_path = Redmine::Configuration['attachments_storage_path'] || "#{RAILS_ROOT}/files"
 
   def validate
     if self.filesize > Setting.attachment_max_size.to_i.kilobytes