Cargo.toml: fixed serde header

Cargo.toml

@@ -55,7 +55,7 @@ clap = "2.33.3"
 toml = "0.5.8"
 dirs = "4.0.0"
 url = "2.2.2"
-serde = "1.0.130"
+serde = {version = "1.0.130", features = ["derive"]}
 serde_json = "1.0.68"
 bytes = "1.0.1"
 signal-hook = "0.3.8"