ssb: Make the invite.use reponse flags match the docs exactly, and add some connection state paranoia.

src/ssb.rpc.c

@@ -1775,10 +1775,16 @@ static void _tf_ssb_invite_use_message_store_callback(const char* id, bool verif
 {
 	invite_t* work = user_data;
 	tf_ssb_connection_t* connection = work->connection;
-	if (verified && is_new)
+	if (verified && is_new && tf_ssb_connection_is_connected(connection) && !tf_ssb_connection_is_closing(connection))
 	{
-		tf_ssb_connection_rpc_send(
-			connection, k_ssb_rpc_flag_json | k_ssb_rpc_flag_end_error, -work->request_number, NULL, (const uint8_t*)work->message, strlen(work->message), NULL, NULL, NULL);
+		tf_ssb_t* ssb = tf_ssb_connection_get_ssb(connection);
+		JSContext* context = tf_ssb_get_context(ssb);
+		JSValue payload = JS_NewObject(context);
+		JSValue message = JS_ParseJSON(context, work->message, strlen(work->message), NULL);
+		JS_SetPropertyStr(context, payload, "key", JS_NewString(context, id));
+		JS_SetPropertyStr(context, payload, "value", message);
+		tf_ssb_connection_rpc_send_json(connection, 0, -work->request_number, NULL, payload, NULL, NULL, NULL);
+		JS_FreeValue(context, payload);
 	}
 	else
 	{