Fixed misleading error message in AbstractRevision.
Fixed misleading error message in AbstractRevision.

onrooby/cruisecontrol.rb,onrooby/cruisecontrol.rb,shopittome/cruisecontrol.rb,thoughtworks/cruisecontrol.rb,thewoolleyman/cruisecontrol.rb,onrooby/cruisecontrol.rb,onrooby/cruisecontrol.rb,shopittome/cruisecontrol.rb,thoughtworks/cruisecontrol.rb,thoughtworks/cruisecontrol.rb,thoughtworks/cruisecontrol.rb,onrooby/cruisecontrol.rb,shopittome/cruisecontrol.rb,shopittome/cruisecontrol.rb,shopittome/cruisecontrol.rb,thoughtworks/cruisecontrol.rb,thewoolleyman/cruisecontrol.rb,shopittome/cruisecontrol.rb