test/rss/test_maker_1.0.rb, test/rss/test_maker_atom_feed.rb:
  RSS 1.0 and Atom feed maker treat maker.channel.language as
  maker.channel.dc_language.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@23445 b2dd03c8-39d4-4d8f-98ff-823fe69b080e