Setting up bitcoin-qt on a new laptop.

Need to tell it to use my desktop as a block source so it goes faster.

There use to be a ~/.bitcoin/bitcoin.conf file where I could do that, but I don't see that file.

What is the current method for telling it to use the "caught up" client I have running on another machine on my gigabit wired LAN ??

Looking via google seems to all point to old documentation for 0.8 client - which used ~/.bitcoin/bitcoin.conf