Fixed no warning compile option.

Author: 5cript

utility/polymorphy.hpp

@@ -13,8 +13,10 @@
 #   error "BOOST_VERSION macro undefined, even though boost/version.hpp is included (broken boost installation?)"
 #endif // BOOST_VERSION
 
-#if BOOST_VERSION < 105600 && !defined(__BORLANDC__) && !defined(JS_DISABLE_BOOST_WARNING)
-#   warning "Polymorphic adaptation is disabled, because the boost version is too old."
+#if BOOST_VERSION < 105600 && !defined(__BORLANDC__)
+#   ifndef JS_DISABLE_BOOST_WARNING
+#       warning "Polymorphic adaptation is disabled, because the boost version is too old."
+#   endif
 #   define DISABLE_POLY_JSON
 #else
 #   include <boost/type_index.hpp>