Close #18 add check deal

dm-cli/Deals.cpp

@@ -538,6 +538,12 @@ int Deals::Cancel()
 
 	nlohmann::json jsonData = nlohmann::json::parse(result);
 	nlohmann::json deal = jsonData["deal"];
+	if (deal == nullptr)
+	{
+		cout << "success: " << jsonData["result"]["success"] << endl;
+		cout << "message: " << jsonData["result"]["message"] << endl;
+		return -1;
+	}
 
 	string message;
 	string sign;