native_tls: switch to using openssl on all platforms

Since we are going to use some openssl-specific features, we will have to remove platform-specific implementations, leaving only openssl.

Author: AlgebraicWolf

Cargo.toml

@@ -14,18 +14,8 @@ rustdoc-args = ["--cfg", "docsrs"]
 
 [features]
 vendored = ["openssl/vendored"]
-alpn = ["security-framework/alpn"]
 
-[target.'cfg(any(target_os = "macos", target_os = "ios"))'.dependencies]
-security-framework = "2.0.0"
-security-framework-sys = "2.0.0"
-libc = "0.2"
-tempfile = "3.1.0"
-
-[target.'cfg(target_os = "windows")'.dependencies]
-schannel = "0.1.17"
-
-[target.'cfg(not(any(target_os = "windows", target_os = "macos", target_os = "ios")))'.dependencies]
+[dependencies]
 log = "0.4.5"
 openssl = "0.10.29"
 openssl-sys = "0.9.55"