fix default plugin_names attribute
fix default plugin_names attribute

shopittome/cruisecontrol.rb,shopittome/cruisecontrol.rb,shopittome/cruisecontrol.rb,thoughtworks/cruisecontrol.rb,thoughtworks/cruisecontrol.rb,shopittome/cruisecontrol.rb,shopittome/cruisecontrol.rb,shopittome/cruisecontrol.rb,thoughtworks/cruisecontrol.rb,thoughtworks/cruisecontrol.rb,thoughtworks/cruisecontrol.rb