go.talks/pkg/socket: fix go-tour non-main package wrong message
go.talks/pkg/socket: fix go-tour non-main package wrong message

Fixes golang/go#5871.

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/11200044

Karthikvb/talks,Karthikvb/talks,Karthikvb/talks,Karthikvb/talks,Karthikvb/talks,Karthikvb/talks