Corrected duplicated file contents

[SVN r47607]

swap/test/mixed_headers_2.cpp

@@ -8,13 +8,5 @@
 
 #include <boost/utility/swap.hpp>
 #include <boost/swap.hpp>
-// Copyright (c) 2007 Joseph Gauterin
-//
-// Distributed under the Boost Software License, Version 1.0.
-// (See accompanying file LICENSE_1_0.txt or copy at
-// http://www.boost.org/LICENSE_1_0.txt)
 
-// Tests that the swap headers work when both are included
 
-#include <boost/utility/swap.hpp>
-#include <boost/swap.hpp>