Consumer Name is required in 2.8.0

[yangou]

Describe the bug
Got below exception trying to connect to pulsar

13:43:29.834 [pulsar-io-29-19] WARN org.apache.pulsar.broker.service.ServerCnx - [/127.0.0.1:61345] Got exception java.lang.IllegalStateException: Field 'consumer_name' is not set
at org.apache.pulsar.common.api.proto.CommandSubscribe.getConsumerName(CommandSubscribe.java:220)
at org.apache.pulsar.broker.service.ServerCnx.handleSubscribe(ServerCnx.java:908)
at org.apache.pulsar.common.protocol.PulsarDecoder.channelRead(PulsarDecoder.java:227)