Bump rocket from 0.4.5 to 0.4.7 in /assets/dockerfiles/base/rust

Bumps [rocket](https://github.com/SergioBenitez/Rocket) from 0.4.5 to 0.4.7.
- [Release notes](https://github.com/SergioBenitez/Rocket/releases)
- [Changelog](https://github.com/SergioBenitez/Rocket/blob/master/CHANGELOG.md)
- [Commits](rwf2/Rocket@v0.4.5...v0.4.7)

---
updated-dependencies:
- dependency-name: rocket
  dependency-type: direct:production
...

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