types/netmap: remove PrivateKey from NetworkMap

It's an unnecessary nuisance having it. We go out of our way to redact
it in so many places when we don't even need it there anyway.

Updates #12639

Change-Id: I5fc72e19e9cf36caeb42cf80ba430873f67167c3
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f