Added debug line to mg_mgr_handle_ctl_sock

    PUBLISHED_FROM=a4c1d105cb4f18d982bd28190691b6ea65ee37fc

mongoose.c

@@ -3142,6 +3142,7 @@ static void mg_mgr_handle_ctl_sock(struct mg_mgr *mgr) {
   struct ctl_msg ctl_msg;
   int len =
       (int) MG_RECV_FUNC(mgr->ctl[1], (char *) &ctl_msg, sizeof(ctl_msg), 0);
+  DBG(("read %d from ctl socket", len));
   size_t dummy = MG_SEND_FUNC(mgr->ctl[1], ctl_msg.message, 1, 0);
   (void) dummy; /* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25509 */
   if (len >= (int) sizeof(ctl_msg.callback) && ctl_msg.callback != NULL) {