cmd/tsconnect/wasm: register netstack.Impl with tsd.System

I missed this in 343c0f1031 and I guess we don't have integration
tests for wasm. But it compiled! :)

Updates #fixup to a #cleanup

Change-Id: If147b90bab254d144ec851a392e8db10ab97f98e
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