Removed unused headers

include/boost/fusion/algorithm/transformation/remove_if.hpp

@@ -1,7 +1,8 @@
 /*=============================================================================
     Copyright (c) 2001-2011 Joel de Guzman
+    Copyright (c) 2018 Kohei Takahashi
 
-    Distributed under the Boost Software License, Version 1.0. (See accompanying 
+    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)
 ==============================================================================*/
 #if !defined(FUSION_REMOVE_IF_07162005_0818)
@@ -10,7 +11,6 @@
 #include <boost/fusion/support/config.hpp>
 #include <boost/fusion/view/filter_view/filter_view.hpp>
 #include <boost/mpl/not.hpp>
-#include <boost/type_traits/is_same.hpp>
 
 namespace boost { namespace fusion
 {