Use our listening Host/IP for outgoing connections also (#226)
Use our listening Host/IP for outgoing connections also (#226)

Explicitely set the local IP for outgoing connections, if we're listening
on only one Hostname or IP (of a multi-IP machine). This makes sure our
peers see our outgoing connections coming from the same IP that we're
listening on when we have a specific HOST= configured.

For machines with more than one IP this avoids source-destination
mismatch errors when advertizing our peer. Resolves kyuupichan/electrumx#225
shsmith/electrumx,Groestlcoin/electrumx-grs,Crowndev/electrumx,erasmospunk/electrumx,thelazier/electrumx,thelazier/electrumx,erasmospunk/electrumx,Crowndev/electrumx,shsmith/electrumx,Groestlcoin/electrumx-grs