Upgrade the rustls dependency to 0.19.

Author: jakubadamw

Cargo.toml

@@ -50,7 +50,7 @@ futures = { version = "0.3.8", optional = true }
 
 # h1_client_rustls
 async-tls = { version = "0.10.0", optional = true }
-rustls_crate = { version = "0.18", optional = true, package = "rustls" }
+rustls_crate = { version = "0.19", optional = true, package = "rustls" }
 
 # hyper_client
 hyper = { version = "0.13.6", features = ["tcp"], optional = true }