fix 'daemon load_wallet' over RPC for python > 3.5.3
fix 'daemon load_wallet' over RPC for python > 3.5.3

related: #3764

spesmilo/electrum,cryptapus/electrum,spesmilo/electrum,fujicoin/electrum-fjc,wakiyamap/electrum-mona,pooler/electrum-ltc,cryptapus/electrum,neocogent/electrum,neocogent/electrum,asfin/electrum,asfin/electrum,vialectrum/vialectrum,neocogent/electrum,wakiyamap/electrum-mona,wakiyamap/electrum-mona,pooler/electrum-ltc,cryptapus/electrum,vialectrum/vialectrum,pooler/electrum-ltc,asfin/electrum,spesmilo/electrum,fujicoin/electrum-fjc,fujicoin/electrum-fjc,vialectrum/vialectrum,wakiyamap/electrum-mona,pooler/electrum-ltc,spesmilo/electrum