Panic in partition multiplexer

[horkhe]

panic: runtime error: invalid memory address or nil pointer dereference [recovered]
        panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x48 pc=0x6b3ec5]

goroutine 2752 [running]:
panic(0x7105e0, 0xc420012030)
        /usr/local/go/src/runtime/panic.go:500 +0x1a1
github.com/mailgun/kafka-pixy/actor.Spawn.func1.1(0xc4206eace0)
        /go/src/github.com/mailgun/kafka-pixy/actor/actor.go:64 +0x1e9
panic(0x7105e0, 0xc420012030)
        /usr/local/go/src/runtime/panic.go:458 +0x243
github.com/mailgun/kafka-pixy/consumer/topiccsm.(*T).Messages(0x0, 0xc421986300)
        /go/src/github.com/mailgun/kafka-pixy/consumer/topiccsm/topiccsm.go:56 +0x5
github.com/mailgun/kafka-pixy/consumer/multiplexer.(*T).run(0xc4200aab40)
        /go/src/github.com/mailgun/kafka-pixy/consumer/multiplexer/multiplexer.go:187 +0x473
github.com/mailgun/kafka-pixy/consumer/multiplexer.(*T).(github.com/mailgun/kafka-pixy/consumer/multiplexer.run)-fm()
        /go/src/github.com/mailgun/kafka-pixy/consumer/multiplexer/multiplexer.go:130 +0x2a
github.com/mailgun/kafka-pixy/actor.Spawn.func1(0xc4200aab78, 0xc4206eace0, 0xc420c13890)
        /go/src/github.com/mailgun/kafka-pixy/actor/actor.go:68 +0xca
created by github.com/mailgun/kafka-pixy/actor.Spawn
        /go/src/github.com/mailgun/kafka-pixy/actor/actor.go:69 +0x58
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
        panic: runtime error: invalid memory address or nil pointer dereference