Set user_id as a protected attribute (#10390).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@9139 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/user_preference.rb

@@ -19,7 +19,7 @@ class UserPreference < ActiveRecord::Base
   belongs_to :user
   serialize :others
 
-  attr_protected :others
+  attr_protected :others, :user_id
 
   before_save :set_others_hash