title: Unknown magic byte with kafka-avro-console-consumer
body: <p>I have been trying to connect with kafka-avro-console-consumer from Confluent to our legacy Kafka cluster, which was deployed without Confluent Schema Registry. 
  I provided schema explicitly using properties like:</p>
  
  <pre><code>kafka-console-consumer --bootstrap-server kafka02.internal:9092 \
      --topic test \
      --from-beginning \
      --property key.schema='{"type":"long"}' \
      --property value.schema='{"type":"long"}'
  </code></pre>
  
  <p>but I am getting 'Unknown magic byte!' error with <code>org.apache.kafka.common.errors.SerializationException</code></p>
  
  <p>Is it possible to consume Avro messages from Kafka using Confluent kafka-avro-console-consumer that were not serialized with AvroSerializer from Confluent and with Schema Registry?</p>