Ignore the unspendable genesis coinbase
Ignore the unspendable genesis coinbase

Fixes #17

thelazier/electrumx,erasmospunk/electrumx,shsmith/electrumx,Groestlcoin/electrumx-grs,Groestlcoin/electrumx-grs,Crowndev/electrumx,bauerj/electrumx,shsmith/electrumx,thelazier/electrumx,bauerj/electrumx,Crowndev/electrumx,erasmospunk/electrumx