Fixed: r4492 breaks the ability to select issue custom fields available for projects issues (#7121).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@4529 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/project.rb

@@ -530,7 +530,8 @@ class Project < ActiveRecord::Base
     'identifier',
     'custom_field_values',
     'custom_fields',
-    'tracker_ids'
+    'tracker_ids',
+    'issue_custom_field_ids'
 
   # Returns an array of projects that are in this project's hierarchy
   #