swaps: rm support for p2wsh-p2sh lockup scripts

- unused
- the client was already refusing to fund such lockup addresses (if the server asked)
- no existing unit tests for it, and as the choice is up to the server, it is hard to create tests
- no clear reason to want to use p2sh-nested scripts here, aside from curiosity

electrum/submarine_swaps.py

@@ -124,14 +124,8 @@ def create_claim_tx(
     """Create tx to either claim successful reverse-swap,
     or to get refunded for timed-out forward-swap.
     """
-    assert txin.address is not None
+    txin.script_type = 'p2wsh'
-    if is_segwit_address(txin.address):
+    txin.script_sig = b''
-        txin.script_type = 'p2wsh'
-        txin.script_sig = b''
-    else:
-        txin.script_type = 'p2wsh-p2sh'  # TODO rm??
-        txin.redeem_script = bytes.fromhex(p2wsh_nested_script(witness_script.hex()))
-        txin.script_sig = bytes.fromhex(push_script(txin.redeem_script.hex()))
     txin.witness_script = witness_script
     txout = PartialTxOutput.from_address_and_value(address, amount_sat)
     tx = PartialTransaction.from_io([txin], [txout], version=2, locktime=locktime)

electrum/tests/test_sswaps.py

@@ -34,7 +34,6 @@ class TestSwapTxs(TestCaseForTestnet):
             prevout=TxOutpoint(txid=bfh(swap_data.funding_txid), out_idx=0),
         )
         txin._trusted_value_sats = swap_data.onchain_amount
-        txin._trusted_address = swap_data.lockup_address
         tx = SwapManager._create_and_sign_claim_tx(
             txin=txin,
             swap=swap_data,
@@ -65,7 +64,6 @@ class TestSwapTxs(TestCaseForTestnet):
             prevout=TxOutpoint(txid=bfh(swap_data.funding_txid), out_idx=0),
         )
         txin._trusted_value_sats = swap_data.onchain_amount
-        txin._trusted_address = swap_data.lockup_address
         tx = SwapManager._create_and_sign_claim_tx(
             txin=txin,
             swap=swap_data,