log: log RPC port on startup
log: log RPC port on startup

I just spent a few hours trying to figure out why "18444" wasn't getting
me to regtest's RPC server. I'm not the sharpest tool in the shed, but I
was maybe understandably confused because "Bound to
127.0.0.1:18445" appears in the logs, which I assumed was the P2P port.

This change logs the RPC listening address, which seems like a basic
piece of information that shouldn't be buried in debug logs.

mruddy/bitcoin,lateminer/bitcoin,lateminer/bitcoin,bitcoin/bitcoin,namecoin/namecoin-core,lateminer/bitcoin,sstone/bitcoin,fanquake/bitcoin,bitcoin/bitcoin,namecoin/namecoin-core,AkioNak/bitcoin,tecnovert/particl-core,bitcoinsSG/bitcoin,AkioNak/bitcoin,jambolo/bitcoin,bitcoin/bitcoin,namecoin/namecoin-core,lateminer/bitcoin,lateminer/bitcoin,kallewoof/bitcoin,kallewoof/bitcoin,ajtowns/bitcoin,bitcoinsSG/bitcoin,bitcoin/bitcoin,ajtowns/bitcoin,sipsorcery/bitcoin,sipsorcery/bitcoin,namecoin/namecoin-core,sstone/bitcoin,sstone/bitcoin,mruddy/bitcoin,fanquake/bitcoin,jambolo/bitcoin,tecnovert/particl-core,jambolo/bitcoin,tecnovert/particl-core,tecnovert/particl-core,mruddy/bitcoin,tecnovert/particl-core,AkioNak/bitcoin,particl/particl-core,particl/particl-core,sstone/bitcoin,kallewoof/bitcoin,sstone/bitcoin,ajtowns/bitcoin,particl/particl-core,bitcoinsSG/bitcoin,AkioNak/bitcoin,ajtowns/bitcoin,fanquake/bitcoin,jambolo/bitcoin,jambolo/bitcoin,mruddy/bitcoin,sipsorcery/bitcoin,bitcoin/bitcoin,bitcoin/bitcoin,kallewoof/bitcoin,particl/particl-core,fanquake/bitcoin,AkioNak/bitcoin,sipsorcery/bitcoin,AkioNak/bitcoin,particl/particl-core,ajtowns/bitcoin,mruddy/bitcoin,namecoin/namecoin-core,bitcoinsSG/bitcoin,sstone/bitcoin,fanquake/bitcoin,bitcoinsSG/bitcoin,sipsorcery/bitcoin,particl/particl-core,kallewoof/bitcoin,ajtowns/bitcoin,lateminer/bitcoin,jambolo/bitcoin,tecnovert/particl-core,sipsorcery/bitcoin,kallewoof/bitcoin,fanquake/bitcoin,namecoin/namecoin-core,bitcoinsSG/bitcoin,mruddy/bitcoin