fix(chat): fix `next_point` on serializer - should return correct value
fix(chat): fix `next_point` on serializer - should return correct value

cjlee112/socraticqs2,cjlee112/socraticqs2,raccoongang/socraticqs2,cjlee112/socraticqs2,cjlee112/socraticqs2,raccoongang/socraticqs2,raccoongang/socraticqs2,raccoongang/socraticqs2