fix signing txs when using old "bitcoin app" (pre-2.1) on the ledger device
```
33.36 | W | transaction | heyheyhey. cp1. include_sigs=True force_legacy=False use_segwit_ser=True
33.36 | W | transaction | heyheyhey. cp2. branch1
33.37 | E | plugins.ledger.ledger |
Traceback (most recent call last):
File "...\electrum\electrum\plugins\ledger\ledger.py", line 669, in sign_transaction
rawTx = tx.serialize_to_network()
File "...\electrum\electrum\transaction.py", line 945, in serialize_to_network
witness = ''.join(self.serialize_witness(x, estimate_size=estimate_size) for x in inputs)
File "...\electrum\electrum\transaction.py", line 945, in <genexpr>
witness = ''.join(self.serialize_witness(x, estimate_size=estimate_size) for x in inputs)
File "...\electrum\electrum\transaction.py", line 839, in serialize_witness
sol = desc.satisfy(allow_dummy=estimate_size, sigdata=txin.part_sigs)
File "...\electrum\electrum\descriptor.py", line 378, in satisfy
sol = self._satisfy_inner(sigdata=sigdata, allow_dummy=allow_dummy)
File "...\electrum\electrum\descriptor.py", line 574, in _satisfy_inner
raise MissingSolutionPiece(f"no sig for {pubkey.hex()}")
electrum.descriptor.MissingSolutionPiece: no sig for 033e92e55923ea25809790f292ee9bd410355ee02492472d9a1ff1b364874d0679
33.38 | I | plugins.ledger.ledger | no sig for 033e92e55923ea25809790f292ee9bd410355ee02492472d9a1ff1b364874d0679
```
fixes https://github.com/spesmilo/electrum/issues/8365
regression from https://github.com/spesmilo/electrum/pull/8230
9e13246be8