fix: Set offered contract to rejected if channel gets cancelled.

dlc-manager/src/manager.rs

@@ -825,8 +825,9 @@ where
     /// message to be sent as well as the public key of the offering node.
     pub fn reject_channel(&self, channel_id: &DlcChannelId) -> Result<(Reject, PublicKey), Error> {
         let offered_channel = get_channel_in_state!(self, channel_id, Offered, None as Option<PublicKey>)?;
+        let offered_contract = get_contract_in_state!(self, &offered_channel.offered_contract_id, Offered, None as Option<PublicKey>)?;
         let counterparty = offered_channel.counter_party;
-        self.store.upsert_channel(Channel::Cancelled(offered_channel), None)?;
+        self.store.upsert_channel(Channel::Cancelled(offered_channel), Some(Contract::Rejected(offered_contract)))?;
 
         let msg = Reject{ channel_id: *channel_id, timestamp: get_unix_time_now() };
         Ok((msg, counterparty))