net/http: add missing ServeTLS on the comment of http.Server.Shutdown
A sentinel error http.ErrServerClosed is returned after Server.Shutdown
and Server.Close but it is not documented on the Server.Shutdown while
other methods such as Server.Serve are documented on it.
Change-Id: Id82886d9d6a1474a514d62e9169b35f3579a9eee
Reviewed-on: https://go-review.googlesource.com/c/go/+/671695 Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Sean Liao <sean@liao.dev> Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Sean Liao <sean@liao.dev>