Is the lump on the right side between the neck and chest?
If so, it is the crop, and is perfectly normal. The crop is where they store food, before digestion. It will go down overnight, as they digest. It will fill up again as they eat.
It could be a problem if it is hard and doesn't go down (impacted), ferments and gets sour (sour crop) or gets large and feels/looks like a big old water balloon (pendulous crop)