[libmicrohttpd] Compile issue

[Markus Doppelbauer]

Current git does not compile without "HAVE_MESSAGES":

This is the context in "daemon.c":

  if ( (0 != (daemon->options & MHD_USE_THREAD_PER_CONNECTION)) &&

       (MHD_NO != ret) )

    { /* Wake up suspended connections. */

      if (! MHD_itc_activate_(daemon->itc,

                              "w"))

#ifdef HAVE_MESSAGES

        MHD_DLOG (daemon,

                  _("Failed to signal resume of connection via inter-thread communication channel."));

#endif

    }