Use the sandwich method. Although you must answer the question, no need to get enthusiastic about what you do not like. Rather start with something positive, related to your issue if possible, and close on an upbeat note. Be factual, but brief when describing your dislikes. If appropriate, express the idea that it is relatively minor and just part of life. In short, try to be as positive as possible about the aspects that you are not comfortable with when answering this question.