fix comment in train file
fix comment in train file

Co-Authored-By: akelad <afb3657645c958bf169590c5b33a84e72c1baeac@users.noreply.github.com>
RasaHQ/rasa_nlu,RasaHQ/rasa_nlu,RasaHQ/rasa_core,RasaHQ/rasa_core,RasaHQ/rasa_nlu,RasaHQ/rasa_core