Remove default for when changing custom field format.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11397 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/controllers/custom_fields_controller.rb

@@ -68,6 +68,8 @@ class CustomFieldsController < ApplicationController
     @custom_field = CustomField.new_subclass_instance(params[:type], params[:custom_field])
     if @custom_field.nil?
       render_404
+    else
+      @custom_field.default_value = nil
     end
   end