Update tokio dep due to a regression in the previous version

Cargo.toml

@@ -19,7 +19,7 @@ clockpro-cache = "0.1.8"
 coarsetime = "0.1.12"
 daemonize-simple = "0.1.4"
 derivative = "2.1.0"
-dnsstamps = "0.1.3"
+dnsstamps = "0.1.4"
 env_logger = { version = "0.7.1", default-features = false, features = ["humantime"] }
 futures = { version = "0.3.4", features = ["async-await"] }
 hyper = { version = "0.13.4", default_features = false, optional = true }
@@ -36,7 +36,7 @@ serde = "1.0.105"
 serde_derive = "1.0.105"
 serde-big-array = "0.2.0"
 siphasher = "0.3.2"
-tokio = { version = "0.2.13", features = ["fs", "rt-threaded", "time", "tcp", "udp", "stream", "parking_lot"] }
+tokio = { version = "0.2.15", features = ["fs", "rt-threaded", "time", "tcp", "udp", "stream", "parking_lot"] }
 toml = "0.5.6"
 
 [dependencies.prometheus]