use require_relative instead of File.expand_path

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@30474 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/net/http/test_http.rb

@@ -3,7 +3,7 @@
 require 'test/unit'
 require 'net/http'
 require 'stringio'
-require File.expand_path("utils", File.dirname(__FILE__))
+require_relative 'utils'
 
 module TestNetHTTP_version_1_1_methods