Maxscale CDC treats unsigned columns as signed

Values in unsigned columns come across in JSON as signed.
In this example, value 8888888 comes across as -7888328.

To reproduce:

CREATE TABLE `unsigned_test` (
`unsigned_test_id` mediumint(8) unsigned DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4;

INSERT INTO `unsigned_test` (`unsigned_test_id`)
VALUES
(3),
(8000000),
(8888888);

JSON Output:

{"namespace": "MaxScaleChangeDataSchema.avro", "type": "record", "name": "ChangeRecord", "fields": [

{"name": "domain", "type": "int"}

,

{"name": "server_id", "type": "int"}

,

{"name": "sequence", "type": "int"}

,

{"name": "event_number", "type": "int"}

,

{"name": "timestamp", "type": "int"}

, {"name": "event_type", "type": {"type": "enum", "name": "EVENT_TYPES", "symbols": ["insert", "update_before", "update_after", "delete"]}},

{"name": "unsigned_test_id", "type": ["null", "int"], "real_type": "mediumint", "length": 8}

]}

{"domain": 0, "server_id": 11009, "sequence": 9780915, "event_number": 1, "timestamp": 1547529921, "event_type": "insert", "unsigned_test_id": 3} {"domain": 0, "server_id": 11009, "sequence": 9781001, "event_number": 1, "timestamp": 1547529930, "event_type": "insert", "unsigned_test_id": 8000000} {"domain": 0, "server_id": 11009, "sequence": 9781377, "event_number": 1, "timestamp": 1547529978, "event_type": "insert", "unsigned_test_id": -7888328}