You're running build 1.8.1S of Tinkers'. I know that build 1.8.4a, as used in the latest Direwolf20 1.7.10 pack, has the config option for villagers (though I don't know if it applies to Iron Golems as well).
If you update Tinkers' Construct, you'll probably also need to update any related mods you may have, such as Iguana Tweaks, Tinkers' Mechworks, etc (I don't have the list of mods from your pack in front of me). It'll be easiest to update your client first, to see what if anything fails. If the latest Tinkers' requires a newer version of Forge, however, your chances of problems with updating will be much greater.
Also keep in mind that anyone who joins your server will likewise need to update their client mods in the same way. If you're running a small server for friends this usually isn't a problem, but if you have a public server you generally want to pick a modpack and stick with what it has.