internal/export/idna: remove spurious comment Change-Id: I44e8cc6d57c1abd9f76645e4548d9bcef8422fb2 Reviewed-on: https://go-review.googlesource.com/34648 Run-TryBot: Marcel van Lohuizen <mpvl@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>