merge revision(s) r45495: [Backport #9662]

	* README.EXT: fix typo.
  [ruby-core:61634] [Bug #9662]

	* README.EXT.ja: ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@46662 b2dd03c8-39d4-4d8f-98ff-823fe69b080e