add NEWS for Random.urandom [ci skip]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57732 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

NEWS

@@ -41,6 +41,9 @@ with all sufficient information, see the ChangeLog file or Redmine
 
 === Compatibility issues (excluding feature bug fixes)
 
+* Random.raw_seed renamed to become Random.urandom.  It is now
+  applicable to non-seeding purposes due to [Bug #9569].
+
 === Stdlib compatibility issues (excluding feature bug fixes)
 
 === C API updates