[atlas] Wrong IP prefix values accepted?

It seems there is no protection against wrong prefixes? See measurement #1897909, which started with JSON: {'definitions': [{'query_class': 'IN', 'description': 'DNS resolution of jihadmin.com from prefix foobar', 'af': 4, 'query_argument': 'jihadmin.com', 'query_type': 'A', 'type': 'dns', 'is_oneoff': True, 'recursion_desired': True, 'use_probe_resolver': True}], 'probes': [{'requested': 3, 'type': 'prefix', 'value': 'foobar'}]}