qt history: fix toggling fiat capital gains
qt history: fix toggling fiat capital gains

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