changed comment

[SVN r10086]

include/boost/concept_check.hpp

@@ -456,7 +456,7 @@ struct require_same { typedef T type; };
       // require iterator_traits typedef's
 #ifndef BOOST_NO_STD_ITERATOR_TRAITS
       typedef typename std::iterator_traits<TT>::difference_type D;
-      // Hmm, this is a bit fragile
+      // Hmm, the following is a bit fragile
       //function_requires< SignedIntegerConcept<D> >();
       typedef typename std::iterator_traits<TT>::reference R;
       typedef typename std::iterator_traits<TT>::pointer P;