Add missing copyright

[skip ci]

db/migrate/20130628092725_add_failed_login_count_last_failed_login_on_to_user.rb

@@ -1,3 +1,15 @@
+#-- encoding: UTF-8
+#-- copyright
+# OpenProject is a project management system.
+#
+# Copyright (C) 2012-2013 the OpenProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# See doc/COPYRIGHT.rdoc for more details.
+#++
+
 class AddFailedLoginCountLastFailedLoginOnToUser < ActiveRecord::Migration
   def change
     add_column :users, :failed_login_count, :integer, :default => 0