Disconnecting while Kafka bridge turned on causes a panic #72
Description
If bridge-way is set to 1, disconnecting an MQTT client causes the following error:
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x18 pc=0xbbee38]
goroutine 51 [running]:
github.com/wind-c/comqtt/v2/plugin/bridge/kafka.(*Bridge).OnDisconnect(0xc000382960, 0xc00011e780, {0x0, 0x0}, 0x68?)
/app/plugin/bridge/kafka/kafka.go:279 +0x98
github.com/wind-c/comqtt/v2/mqtt.(*Hooks).OnDisconnect(0xc00030c2a0?, 0xd628c1?, {0x0, 0x0}, 0x3?)
/app/mqtt/hooks.go:265 +0x13c
github.com/wind-c/comqtt/v2/mqtt.(*Server).attachClient(0xc000382190, 0xc00011e780, {0xd54ca3, 0x3})
/app/mqtt/server.go:381 +0x7c5
github.com/wind-c/comqtt/v2/mqtt.(*Server).EstablishConnection(0x8747ae?, {0xd54ca3, 0x3}, {0xe712a8?, 0xc000012008?})
/app/mqtt/server.go:311 +0x65
github.com/wind-c/comqtt/v2/mqtt/listeners.(*TCP).Serve.func1()
/app/mqtt/listeners/tcp.go:84 +0x47
created by github.com/wind-c/comqtt/v2/mqtt/listeners.(*TCP).Serve
/app/mqtt/listeners/tcp.go:83 +0x145
Not sure if it's because the client has already disconnected or what.