remove openssl dependency from reqwest

https://github.com/GoogleChrome/ripunzip/blob/89627f0ac7814640eb02644c2ed5f28994e8b5e5/Cargo.toml#L33
`reqwest` supports `rustls`.

I just don't want depend on `openssl` (if `rustls` does not cause serious performance drop).

Start at Cargo.toml line 33 and inspect the reqwest dependency features. Switch the configuration away from openssl using reqwest's supported alternative, then run the project's Rust build and tests. Done means the project builds and tests pass without pulling in openssl.

Written by the indexing model from the issue text.