fail_swap: do not remove swap if it has been funded

electrum/submarine_swaps.py

@@ -269,6 +269,7 @@ class SwapManager(Logger):
             payment_key = swap.payment_hash + payment_secret
             self.lnworker.fail_final_onion_forwarding(payment_key)
         self.lnwatcher.remove_callback(swap.lockup_address)
+        if swap.funding_txid is None:
             self.swaps.pop(swap.payment_hash.hex())
 
     @log_exceptions