Force the default value of path to be set on the Change model class. #5771

This is needed because MySQL does not support default values on text columns
(Error introduced in r3828)

Contributed by Holger Just

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@3830 e93f8b46-1217-0410-a6f0-8f06a7374b81

db/migrate/20100705164950_change_changes_path_length_limit.rb

@@ -1,6 +1,6 @@
 class ChangeChangesPathLengthLimit < ActiveRecord::Migration
   def self.up
-    change_column :changes, :path, :text, :default => "", :null => false
+    change_column :changes, :path, :text, :null => false
     change_column :changes, :from_path, :text
   end