Probably something stuck in its throat. Just spit balling here (excuse the pun) Is it continuous, been happening for days, just once. I am not sure I would think anything of it unless it is happening alot. A little gentle crop massage would not hurt anything and maybe a drop of olive oil down the throat. I would hesitate to interfer unless you think it is needed. The chick is trying to get out whatever for a reason. You could also offer soft food to make eating easier, just add water to the food and smash it up into the consistency of runny oatmeal.
My motto is first "Do no harm". Sometimes treatments are more hurtful than what is already happening.
Good luck