lnpeer: fix json serialization of funding_inputs

electrum/lnpeer.py

@@ -594,7 +594,7 @@ class Peer(Logger):
                        sweep_address=self.lnworker.sweep_address,
                        lnworker=self.lnworker,
                        initial_feerate=feerate)
-        chan.storage['funding_inputs'] = [txin.prevout for txin in funding_tx.inputs()]
+        chan.storage['funding_inputs'] = [txin.prevout.to_json() for txin in funding_tx.inputs()]
         sig_64, _ = chan.sign_next_commitment()
         self.temp_id_to_id[temp_channel_id] = channel_id
         self.send_message("funding_created",

electrum/transaction.py

@@ -180,6 +180,9 @@ class TxOutpoint(NamedTuple):
     def to_str(self) -> str:
         return f"{self.txid.hex()}:{self.out_idx}"
 
+    def to_json(self) -> str:
+        return [self.txid.hex(), self.out_idx]
+
     def serialize_to_network(self) -> bytes:
         return self.txid[::-1] + bfh(int_to_hex(self.out_idx, 4))