Fix #1473 - Omit bitcoincash: prefix from legacy addr in receive tab QR
Fix #1473 - Omit bitcoincash: prefix from legacy addr in receive tab QR

This allows users to use the receive tab to scan the QR code in legacy
mode without the bitcoincash: prefix, which confuses some wallets.

Thanks for im_uname for pointing this out.

fyookball/electrum,fyookball/electrum,fyookball/electrum