http://127.0.0.1:8080/users Post 注册用户时， 等待一段时间后返回 user already exist
这是服务器返回的：
Transaction processing for endorser [127.0.0.1:27051]: Chaincode status Code: (500) UNKNOWN. Description: user already exist

这是控制台日志

[fabsdk/fab] 2018/10/11 11:15:19 UTC - client.(*Client).connectWithRetry -> WARN … connection attempt failed: error invoking afterConnect handler: error sending seek info for channel [assetschannel]: EOF

[fabsdk/fab] 2018/10/11 11:24:30 UTC - client.(*Client).monitorConnection -> WARN Event client has disconnected. Details: rpc error: code = Unimplemented desc = unknown service protos.Deliver