minor: use correct boost header for string_ref

acmorrow · acmorrow · commit 7530d86c1181 · 2017-11-16T18:22:20.000-05:00
diff --git a/src/bsoncxx/stdx/string_view.hpp b/src/bsoncxx/stdx/string_view.hpp
@@ -56,7 +56,7 @@ BSONCXX_INLINE_NAMESPACE_END
 
 #else
 
-#include <boost/utility/string_view.hpp>
+#include <boost/utility/string_ref.hpp>
 
 namespace bsoncxx {
 BSONCXX_INLINE_NAMESPACE_BEGIN
