Merge pull request async-rs#72 from kallisti5/socket-bump

cargo: Bump socket2 to 0.4.2 for Haiku, BSD fixes

Author: taiki-e

Cargo.toml

@@ -22,7 +22,7 @@ once_cell = "1.4.1"
 parking = "2.0.0"
 polling = "2.0.0"
 slab = "0.4.2"
-socket2 = { version = "0.4.0", features = ["all"] }
+socket2 = { version = "0.4.2", features = ["all"] }
 waker-fn = "1.1.0"
 
 [target."cfg(unix)".dependencies]