fix #2861: error message when password is missing
fix #2861: error message when password is missing

spesmilo/electrum,pooler/electrum-ltc,dabura667/electrum,wakiyamap/electrum-mona,fujicoin/electrum-fjc,cryptapus/electrum,fyookball/electrum,fujicoin/electrum-fjc,dabura667/electrum,romanz/electrum,neocogent/electrum,kyuupichan/electrum,wakiyamap/electrum-mona,neocogent/electrum,digitalbitbox/electrum,romanz/electrum,wakiyamap/electrum-mona,asfin/electrum,fyookball/electrum,kyuupichan/electrum,wakiyamap/electrum-mona,vialectrum/vialectrum,vialectrum/vialectrum,digitalbitbox/electrum,romanz/electrum,asfin/electrum,kyuupichan/electrum,cryptapus/electrum,pooler/electrum-ltc,fujicoin/electrum-fjc,digitalbitbox/electrum,cryptapus/electrum,asfin/electrum,fyookball/electrum,pooler/electrum-ltc,spesmilo/electrum,neocogent/electrum,vialectrum/vialectrum,spesmilo/electrum,dabura667/electrum,spesmilo/electrum,digitalbitbox/electrum,pooler/electrum-ltc,dabura667/electrum