Remove AP_FAILURE spamming

And adding rc_lost message, which is not fully functional yet. It seems
to only say it once in a session.

sw/ground_segment/cockpit/live.ml

@@ -869,9 +869,9 @@ let get_fbw_msg = fun alarm _sender vs ->
   (* divide by 5 to have normal values between 0 and 10 *)
   (* RC rate max approx. 50 Hz *)
   ac.strip#set_rc rate status;
-  let mode = PprzLink.string_assoc "rc_mode" vs in
-  if mode = "FAILSAFE" then begin
-    log_and_say alarm ac.ac_name (sprintf "%s, mayday, AP Failure. Switch to manual." ac.ac_speech_name)
+  let rc = PprzLink.string_assoc "rc_status" vs in
+  if (rc = "LOST") || (rc = "REALLY_LOST") then begin
+    log_and_say alarm ac.ac_name (sprintf "%s, RC lost." ac.ac_speech_name)
   end
 
 let get_telemetry_status = fun alarm _sender vs ->