f account for having a RouteHop for intro node and fix bug

Author: valentinewallace

lightning/src/ln/channelmanager.rs

@@ -6892,7 +6892,7 @@ impl Readable for HTLCSource {
 					payment_id = Some(PaymentId(*session_priv.0.unwrap().as_ref()));
 				}
 				let path = path.unwrap_or(Vec::new());
-				if path.is_empty() && blinded_tail.is_none() {
+				if path.is_empty() {
 					return Err(DecodeError::InvalidValue);
 				}
 				if let Some(params) = payment_params.as_mut() {
@@ -6903,7 +6903,7 @@ impl Readable for HTLCSource {
 				Ok(HTLCSource::OutboundRoute {
 					session_priv: session_priv.0.unwrap(),
 					first_hop_htlc_msat,
-					path: Path { hops: path, blinded_tail: None },
+					path: Path { hops: path, blinded_tail },
 					payment_id: payment_id.unwrap(),
 				})
 			}