Bump rustup from `b9e968b` to `1a46072`
Bump rustup from `b9e968b` to `1a46072`

Bumps [rustup](https://github.com/rust-lang-nursery/rustup.rs) from `b9e968b` to `1a46072`.
- [Release notes](https://github.com/rust-lang-nursery/rustup.rs/releases)
- [Commits](https://github.com/rust-lang-nursery/rustup.rs/compare/b9e968b6656dd999eb09fb6dc8e7952677dd3fc2...1a46072ac0a82d3a2dcd38a0afdcc2c7caa69507)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
nrc/rustc-perf,nrc/rustc-perf,nrc/rustc-perf