Bump rand from 0.8.3 to 0.8.4

Bumps [rand](https://github.com/rust-random/rand) from 0.8.3 to 0.8.4.
- [Release notes](https://github.com/rust-random/rand/releases)
- [Changelog](https://github.com/rust-random/rand/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rust-random/rand/compare/0.8.3...0.8.4)

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

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

Cargo.toml

@@ -33,7 +33,7 @@ base64 = "0.13.0"
 num-bigint = "0.4.0"
 num-traits = "0.2.14"
 chrono = { version = "0.4.19", features = ["serde"] }
-rand = { version = "0.8.3", package = "rand" }
+rand = { version = "0.8.4", package = "rand" }
 rand-old = { package = "rand", version = "0.7.0" } # For ed25519-dalek
 sqlite = "0.26.0"
 uuid = { version = "0.8.2", features = ["serde", "v4"] }