message: reactor.network.socket: Do not throw raw boost::system::system_error.
diff: @@ -306,7 +306,7 @@ namespace reactor
  boost::system::error_code e;
  socket.cancel(e);
  if (e && e != boost::asio::error::bad_descriptor)
  - throw boost::system::system_error(e);
  + throw Exception(e.message());
  socket.close();
  }
  