ChangeLog: fix a typo for r47897.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47905 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2014-10-14

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47906 b2dd03c8-39d4-4d8f-98ff-823fe69b080e