Test for unknown HTLC intercept id error

Author: valentinewallace

lightning/src/ln/payment_tests.rs

@@ -1562,5 +1562,7 @@ fn do_test_intercepted_payment(test: InterceptTest) {
 		let (_, channel_id) = open_zero_conf_channel(&nodes[1], &nodes[2], None);
 		let unknown_intercept_id_err = nodes[1].node.forward_intercepted_htlc(intercept_id, &channel_id, nodes[2].node.get_our_node_id(), expected_outbound_amount_msat).unwrap_err();
 		assert_eq!(unknown_intercept_id_err , APIError::APIMisuseError { err: format!("Payment with intercept id {} not found", log_bytes!(intercept_id.0)) });
+		let unknown_intercept_id_err = nodes[1].node.fail_intercepted_htlc(intercept_id).unwrap_err();
+		assert_eq!(unknown_intercept_id_err , APIError::APIMisuseError { err: format!("Payment with intercept id {} not found", log_bytes!(intercept_id.0)) });
 	}
 }