Clone the input slice before adjusting NextProtos
to add or remove "http/1.1" and "h2" entries,
so as not to modify a slice that the caller might be using.
(We clone the tls.Config that contains the slice, but
that's a shallow clone.)
Fixes #72100
Change-Id: I9f228b8fb6f6f2ca5023179ec114929c002dbda9
Reviewed-on: https://go-review.googlesource.com/c/go/+/654875 Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Auto-Submit: Damien Neil <dneil@google.com> Reviewed-by: Jonathan Amsterdam <jba@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>