Bump socket2 from 0.3.10 to 0.3.11 (#5451)

Bumps [socket2](https://github.com/alexcrichton/socket2-rs) from 0.3.10 to 0.3.11.
- [Release notes](https://github.com/alexcrichton/socket2-rs/releases)
- [Commits](https://github.com/alexcrichton/socket2-rs/compare/0.3.10...0.3.11)

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

netutil/Cargo.toml

@@ -14,7 +14,7 @@ clap = "2.33.0"
 log = "0.4.8"
 nix = "0.14.1"
 rand = "0.6.1"
-socket2 = "0.3.9"
+socket2 = "0.3.11"
 solana-logger = { path = "../logger", version = "0.18.0-pre1" }
 tokio = "0.1"