fix get_balance method
fix get_balance method

spesmilo/electrum,wakiyamap/electrum-mona,pooler/electrum-ltc,wakiyamap/electrum-mona,pooler/electrum-ltc,spesmilo/electrum,spesmilo/electrum,spesmilo/electrum,pooler/electrum-ltc,pooler/electrum-ltc,wakiyamap/electrum-mona,wakiyamap/electrum-mona