I bought the stick in the summer and got version 3. From version 2, the stick is equipped with the Realtek RTL8188EUS chip.
However, since I needed the Atheros AR9271, I had to get a version 1. However, I only found this one second-hand.
So contrary to the first answer, I think the wifi stick still has version 3 and therefore does not come with the Atheros AR9271.

My guess is that since it's still a USB 2.0 port, it's still the same chipset as it was back then. So it's an Atheros AR9271.