Bump tower from 0.5.1 to 0.5.2

Bumps [tower](https://github.com/tower-rs/tower) from 0.5.1 to 0.5.2.
- [Release notes](https://github.com/tower-rs/tower/releases)
- [Commits](tower-rs/tower@tower-0.5.1...tower-0.5.2)

---
updated-dependencies:
- dependency-name: tower
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>