chore(deps): bump handlebars from 3.5.5 to 4.1.1

Bumps [handlebars](https://github.com/sunng87/handlebars-rust) from 3.5.5 to 4.1.1.
- [Release notes](https://github.com/sunng87/handlebars-rust/releases)
- [Changelog](https://github.com/sunng87/handlebars-rust/blob/master/CHANGELOG.md)
- [Commits](sunng87/handlebars-rust@v3.5.5...v4.1.1)

---
updated-dependencies:
- dependency-name: handlebars
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

Cargo.lock

@@ -36,7 +36,7 @@ futures = "0.3"
 flate2 = "1.0"
 http = "0.2"
 http-auth-basic = "0.2.2"
-handlebars = "3"
+handlebars = "4"
 hyper = { version = "0.14", features = ["http1", "server", "stream", "tcp"] }
 local-ip-address = "0.4.2"
 mime_guess = "2"