[Debug] use Sys.sigint instead of 24

src/util/debug.ml

@@ -239,7 +239,7 @@ let () = at_exit (fun () ->
 (** SIGXCPU cpu time limit reached *)
 let _ =
   (** TODO? have a possible callback for printing different message*)
-  Sys.signal 24 (Sys.Signal_handle (fun _ -> exit 2))
+  Sys.signal Sys.sigint (Sys.Signal_handle (fun _ -> exit 2))
 
 let register_stats ~print ~name ~init =
   let s = ref init in