tell crates-index which http library to choose

[syphar]

I tried to run the database synchronize command and got this error:

$ cratesfyi database synchronize --dry-run
{"timestamp":"2025-09-11T17:22:00.225643Z","level":"INFO","fields":{"message":"Loading data from database..."},"target":"docs_rs::utils::consistency"}
{"timestamp":"2025-09-11T17:22:00.227775Z","level":"DEBUG","fields":{"message":"creating database pool (if this hangs, consider running `docker-compose up -d db s3`)"},"target":"docs_rs::db::pool"}
{"timestamp":"2025-09-11T17:22:20.109146Z","level":"INFO","fields":{"message":"Loading data from index..."},"target":"docs_rs::utils::consistency"}
{"timestamp":"2025-09-11T17:22:20.128522Z","level":"DEBUG","fields":{"message":"Opening with `crates_index`"},"target":"docs_rs::index"}
Error: Loading crate data from index for consistency check

Caused by:
    Loading crate data from index for consistency check

Caused by:
    "gix" crate failed. If problems persist, consider deleting `~/.cargo/registry/index/github.com-1ecc6299db9ec823/`

Caused by:
    'https' is not compiled in. Compile with the 'http-client-curl' or 'http-client-reqwest' cargo feature

Stack backtrace:
   0: anyhow::error::<impl core::convert::From<E> for anyhow::Error>::from
   1: docs_rs::utils::consistency::index::load
   2: docs_rs::utils::spawn_blocking::{{closure}}::{{closure}}
   3: tokio::runtime::task::core::Core<T,S>::poll
   4: tokio::runtime::task::harness::Harness<T,S>::poll
   5: tokio::runtime::blocking::pool::Inner::run
   6: std::sys::backtrace::__rust_begin_short_backtrace
   7: core::ops::function::FnOnce::call_once{{vtable.shim}}
   8: std::sys::pal::unix::thread::Thread::new::thread_start
   9: start_thread
             at /build/glibc-uZu3wS/glibc-2.27/nptl/pthread_create.c:463:0
  10: __clone
             at /build/glibc-uZu3wS/glibc-2.27/misc/../sysdeps/unix/sysv/linux/x86_64/clone.S:95:0

Related crates-index commits:

• frewsxcv/rust-crates-index@a8953e0#diff-2e9d962a08321605940b5a657135052fbcef87b5e360662bb527c96d9a615542
• frewsxcv/rust-crates-index@d003e69

previously the curl engine was the default, which is why I chose it. I checked if using the reqwests engine would add less dependencies, but it doesn't make a difference.