Bump socket2 from 0.5.1 to 0.5.3

Bumps [socket2](https://github.com/rust-lang/socket2) from 0.5.1 to 0.5.3.
- [Release notes](https://github.com/rust-lang/socket2/releases)
- [Changelog](https://github.com/rust-lang/socket2/blob/master/CHANGELOG.md)
- [Commits](rust-lang/socket2@v0.5.1...v0.5.3)

---
updated-dependencies:
- dependency-name: socket2
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Cargo.toml

@@ -41,7 +41,7 @@ slog = { version = "2.7", features = ["max_level_trace", "release_max_level_trac
 slog-async = "2.6"
 slog-term = "2.9"
 smoltcp = { version = "0.9", default-features = false, features = ["proto-ipv6"] }
-socket2 = "0.5.1"
+socket2 = "0.5.3"
 static_assertions = "1.1.0"
 string_cache = "0.8.4"
 termios = "0.3"