Some missing variable replacements for index `dl` url

[Nemo157]

rustwide/src/crates/registry.rs

Line 103 in 76a2475

let replacements = [("{crate}", &self.name), ("{version}", &self.version)];

Based on https://doc.rust-lang.org/nightly/cargo/reference/registries.html#index-format this is missing the prefix, lowerprefix and sha256-checksum variables that were introduced.