Merging two Electrum wallets together causes an assertion

[sophom]

When trying to merge two electrum wallets together, the "assert len(transactions) == 1" in merge asserts.

For example let's just say you created a segwit wallet after happily using the old style wallet. Then you moved your bitcoin from the old wallet to the new segwit wallet. When entering both wallet csvs on the command line, the above assertion will assert on the transaction that transfers the funds from the old wallet to the new wallet.

Adding the below to the ElectrumParser seems to fix the problem:

def merge_some(self, transactions):
    return transactions