Fixed rust build

pkgs/rust/openbsd-libressl.patch

@@ -0,0 +1,14 @@
+$OpenBSD: patch-vendor_openssl-sys_build_main_rs,v 1.5 2020/11/05 09:21:34 semarie Exp $
+The LibreSSL version in -current isn't explicitly supported.
+Index: vendor/openssl-sys/build/main.rs
+--- a/vendor/openssl-sys/build/main.rs.orig
++++ b/vendor/openssl-sys/build/main.rs
+@@ -221,7 +221,7 @@ See rust-openssl README for more information:
+             (3, 1, 0) => ('3', '1', '0'),
+             (3, 1, _) => ('3', '1', 'x'),
+             (3, 2, 0) => ('3', '2', '0'),
+-            _ => version_error(),
++            _ => ('3', '2', '0'),
+         };
+ 
+         println!("cargo:libressl=true");