Makes the app boot with Rails 2.2.2

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@2227 e93f8b46-1217-0410-a6f0-8f06a7374b81

config/initializers/10-patches.rb

@@ -12,6 +12,6 @@ ActiveRecord::Errors.default_error_messages = {
   :wrong_length => "activerecord_error_wrong_length",
   :taken => "activerecord_error_taken",
   :not_a_number => "activerecord_error_not_a_number"
-}
+} if ActiveRecord::Errors.respond_to?('default_error_messages=')
 
 ActionView::Base.field_error_proc = Proc.new{ |html_tag, instance| "#{html_tag}" }