Bump rustup from 0fada4f to 3423488

Bumps [rustup](https://github.com/rust-lang-nursery/rustup.rs) from `0fada4f` to `3423488`.
- [Release notes](https://github.com/rust-lang-nursery/rustup.rs/releases)
- [Commits](rust-lang/rustup@0fada4f...3423488)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]