MXS-1316: Read the raw input in cdc_kafka_producer.py

The input can be read as raw bytes since kafka expects the data to be of
type bytes instead of str.

server/modules/protocol/examples/cdc_kafka_producer.py

@@ -30,6 +30,7 @@ parser.add_argument("-T", "--kafka-topic", dest="kafka_topic",
 
 opts = parser.parse_args(sys.argv[1:])
 producer = KafkaProducer(bootstrap_servers=[opts.kafka_broker])
+sys.stdin = sys.stdin.detach()
 
 while True:
    try: