cargo-vendor broken with openssl 3?

[Jakub Bogusz]

```
[qboosh at carme-pld dssim-3.0.2]$ cargo vendor
    Updating crates.io index
error: failed to sync

Caused by:
  failed to load pkg lockfile

Caused by:
  failed to get `imgref` as a dependency of package `dssim-core v3.1.0 (/home/users/qboosh/rpm/BUILD/dssim-3.0.2/dssim-core)`

Caused by:
  failed to fetch `https://github.com/rust-lang/crates.io-index`

Caused by:
  network failure seems to have happened
  if a proxy or similar is necessary `net.git-fetch-with-cli` may help here
  https://doc.rust-lang.org/cargo/reference/config.html#netgit-fetch-with-cli

Caused by:
  the SSL certificate is invalid; class=Ssl (16); code=Certificate (-17)
```

Fetching `https://github.com/rust-lang/crates.io-index` with curl works.

cargo-vendor works for me with rust 1.57.0 built with openssl 1.1.1l.


-- 
Jakub Bogusz    http://qboosh.pl/