Mistake in ThOr transition tutorial

The doc/tutorials/thor_transition.rst says the LoKi APT functor should be replaced by F.SUM(F.PT). However, the Functor translation table suggests APT -> F.PT. I've tested this with the pid/Hlt/Hlt2Conf/python/Hlt2Conf/lines/pid/DstToD0Pi_D0ToKPi.py line and F.SUM(F.PT) gives different results than APT while F.PT gives results identical to APT.