If you add a `SetName(name string)` method to *HttpInput, then Heka will pass in the name of the input plugin before config happens. You can store this and then (before the for loop) set a `logger` value to `fmt.Sprintf("HttpInput: %s", hi.Name)` and then `pack.Message.SetLogger(logger)` to distinguish btn multiple HttpInputs running in the same Heka.