Re-add rustls support and enable it by default

rustls is seen as mature enough for curl to depend on it optionally,
and it recently has had an audit.

This commit adds back rustls support removed by 86bb185
and enables it by default.

Cargo.toml

@@ -13,9 +13,14 @@ version = "1.22.1"
 
 [features]
 curl-backend = ["download/curl-backend"]
-default = ["curl-backend", "reqwest-backend"]
+default = ["curl-backend", "reqwest-backend", "reqwest-rustls-tls"]
+
 reqwest-backend = ["download/reqwest-backend"]
 vendored-openssl = ['openssl/vendored']
+
+reqwest-default-tls = ["download/reqwest-default-tls"]
+reqwest-rustls-tls = ["download/reqwest-rustls-tls"]
+
 # Include in the default set to disable self-update and uninstall.
 no-self-update = []
 
@@ -25,7 +30,7 @@ anyhow = "1.0.31"
 cfg-if = "0.1"
 chrono = "0.4"
 clap = "2"
-download = {path = "download"}
+download = { path = "download", default-features = false }
 error-chain = "0.12"
 flate2 = "1"
 git-testament = "0.1.4"

download/Cargo.toml

@@ -9,18 +9,20 @@ license = "MIT/Apache-2.0"
 
 [features]
 
-default = ["reqwest-backend"]
+default = ["reqwest-backend", "reqwest-rustls-tls"]
 
 curl-backend = ["curl"]
 reqwest-backend = ["reqwest", "env_proxy", "lazy_static"]
+reqwest-default-tls = ["reqwest/default-tls"]
+reqwest-rustls-tls = ["reqwest/rustls-tls"]
 
 [dependencies]
 error-chain = "0.12"
 url = "2.1"
 curl = { version = "0.4.11", optional = true }
 env_proxy = { version = "0.4.1", optional = true }
 lazy_static = { version = "1.0", optional = true }
-reqwest = { version = "0.10", features = ["blocking", "gzip", "socks"], optional = true }
+reqwest = { version = "0.10", default-features = false, features = ["blocking", "gzip", "socks"], optional = true }
 
 [dev-dependencies]
 hyper = { version = "0.13", default-features = false, features = ["tcp"] }