Bump diesel from 2.2.1 to 2.2.2

Bumps [diesel](https://github.com/diesel-rs/diesel) from 2.2.1 to 2.2.2.
- [Release notes](https://github.com/diesel-rs/diesel/releases)
- [Changelog](https://github.com/diesel-rs/diesel/blob/v2.2.2/CHANGELOG.md)
- [Commits](diesel-rs/diesel@v2.2.1...v2.2.2)

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

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

Cargo.toml

@@ -12,7 +12,7 @@ rocket = "0.5.1"
 serde = "1.0.208"
 serde_json = "^1.0"
 serde_derive = "1.0.126"
-diesel = { version = "^2.1", features = ["sqlite", "r2d2", "chrono"] }
+diesel = { version = "^2.2", features = ["sqlite", "r2d2", "chrono"] }
 diesel_migrations = "^2.2"
 log = "^0.4"
 chrono = { version = "^0.4", features = ["serde"] }