Mmm that is missing the horn wiring then. That connector in your pic is for the tiptronic buttons. I mis-spoke (typed?) about the black plug - its yellow you need. The horn wiring is on the airbag harness which you are missing. It has the yellow connector for the airbag itself, another yellow connector to the slip ring, and then two spade connectors which go on to the tab you can see on the right of your pic plus another one out of sight just above it (all circled below)
You can actually ignore the black connector since you don't need the tip buttons.