Cargo: Add rustls

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

Cargo.toml

@@ -22,6 +22,7 @@ rand = "0.8.3"
 url = "2.1.0"
 hyper-native-tls = { version = "0.3.0", optional = true }
 openssl = { version = "0.10", features = ["vendored"], optional = true }
+rustls = { version = "0.20", optional = true }
 mime_guess = "2.0"
 open = "1"
 # Iron crates
@@ -33,6 +34,6 @@ percent-encoding = "2.1.0"
 path-dedot = "1"
 
 [features]
-default = ["tls"]
-only-openssl = ["tls", "openssl"]
-tls = ["hyper-native-tls"]
+default = ["native-tls"]
+only-openssl = ["native-tls", "openssl"]
+native-tls = ["hyper-native-tls"]