In Europe, a second KitKat update for the HTC One is rolling out0
According to the changelist, the update brings software version 4.19.401.11 to HTC's current flagship model,and weighs in at a hefty 205MB. The update brings support for more routers, which suggests that a lack of compatibility with the routers used by some HTC One owners was responsible for the problems with the initial update.
The update is coming OTA and you can try to coax it out of your phone by going to Settings > About phone > Software updates. Keep in mind that KitKat is being sent out in waves, so if it doesn't come to your phone today, relax. You will soon receive it.