I would put 30kt headwind in the FMGS and compute landing distance (QRH) with zero headwind. In the worst case scenario (zero headwind at time of touch) I would have +5 knots on my Vapp (Vls+10 instead of Vls+5).
On the other hand if I put 0 headwind in the FMGC and in the worst case I had 30kt headwind at the time of touch, instead of the needed Vls+10 I would have Vapp+20kt (GSmini, which in our case is Vapp-10, plus current wind component) that would be Vls+25kt. Not true?