Rails3: test: replace deprecated Errors#on to Errors#[] and join with to_s at test/unit/repository_test.rb

On Rails2, Errors#[] returns single error if one error raises.
But, on Rails3, Errors#[] always returns the array.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@8135 e93f8b46-1217-0410-a6f0-8f06a7374b81

test/unit/repository_test.rb

@@ -68,7 +68,7 @@ class RepositoryTest < ActiveSupport::TestCase
                       :project => Project.find(3), :url => "svn://localhost")
       assert !repository.save
       assert_equal I18n.translate('activerecord.errors.messages.invalid'),
-                                  repository.errors.on(:type)
+                                  repository.errors[:type].to_s
     end
   end