doc/NEWS-2.5.0: Time.at is a class method

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61673 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

doc/NEWS-2.5.0

@@ -209,7 +209,7 @@ with all sufficient information, see the ChangeLog file or Redmine
 
 * Time
 
-  * Time#at receives 3rd argument which specifies the unit of 2nd argument.
+  * Time.at receives 3rd argument which specifies the unit of 2nd argument.
     [Feature #13919]
 
 * KeyError