Bump tonic from 0.7.1 to 0.7.2

Bumps [tonic](https://github.com/hyperium/tonic) from 0.7.1 to 0.7.2.
- [Release notes](https://github.com/hyperium/tonic/releases)
- [Changelog](https://github.com/hyperium/tonic/blob/master/CHANGELOG.md)
- [Commits](hyperium/tonic@v0.7.1...v0.7.2)

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

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