x509roots/fallback: update bundle

This is an automated CL which updates the NSS root bundle.

[git-generate]
go generate ./x509roots

Change-Id: If1970af8da68ead595dc3fa7dd79a8555a5f09c5
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/668576
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Roland Shoemaker <roland@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Gopher Robot <gobot@golang.org>

Author: gopherbot