Bump env_logger from 0.8.4 to 0.9.0

Bumps [env_logger](https://github.com/env-logger-rs/env_logger) from 0.8.4 to 0.9.0.
- [Release notes](https://github.com/env-logger-rs/env_logger/releases)
- [Changelog](https://github.com/env-logger-rs/env_logger/blob/main/CHANGELOG.md)
- [Commits](https://github.com/env-logger-rs/env_logger/compare/v0.8.4...v0.9.0)

---
updated-dependencies:
- dependency-name: env_logger
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

rust/sync-server/Cargo.toml

@@ -17,7 +17,7 @@ serde = "^1.0.125"
 serde_json = "^1.0"
 clap = "^2.33.0"
 log = "^0.4.17"
-env_logger = "^0.8.3"
+env_logger = "^0.9.0"
 rusqlite = { version = "0.27", features = ["bundled"] }
 chrono = { version = "^0.4.10", features = ["serde"] }