doc: explain why cmd/go uses https for repositories and how to work around it Fixes issue 3418.
doc: explain why cmd/go uses https for repositories and how to work around it
Fixes issue 3418.

R=golang-dev, r
CC=adg, golang-dev
https://codereview.appspot.com/7712045

Committer: Rob Pike <4dc7c9ec434ed06502767136789763ec11d2c4b7@golang.org>
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go