Bump chrono from 0.4.6 to 0.4.7 (#4812)

Bumps [chrono](https://github.com/chronotope/chrono) from 0.4.6 to 0.4.7.
- [Release notes](https://github.com/chronotope/chrono/releases)
- [Changelog](https://github.com/chronotope/chrono/blob/master/CHANGELOG.md)
- [Commits](https://github.com/chronotope/chrono/compare/v0.4.6...v0.4.7)

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

core/Cargo.toml

@@ -21,7 +21,7 @@ kvstore = ["solana-kvstore"]
 bincode = "1.1.4"
 bs58 = "0.2.0"
 byteorder = "1.3.2"
-chrono = { version = "0.4.0", features = ["serde"] }
+chrono = { version = "0.4.7", features = ["serde"] }
 core_affinity = "0.5.9"
 crc = { version = "1.8.1", optional = true }
 hashbrown = "0.2.0"