Revert "gnu: Add rust-libressl-pnacl-sys-2."

This crate includes a vendored copy of libressl.

This reverts commit a86fc40dc3.

gnu/packages/crates-io.scm

@@ -8160,30 +8160,6 @@ functions and static variables these libraries contain.")
         (base32
          "16pc0gx4gkg0q2s1ssq8268brn14j8344623vwhadmivc4lsmivz"))))))
 
-(define-public rust-libressl-pnacl-sys-2
-  (package
-    (name "rust-libressl-pnacl-sys")
-    (version "2.1.6")
-    (source
-     (origin
-       (method url-fetch)
-       (uri (crate-uri "libressl-pnacl-sys" version))
-       (file-name
-        (string-append name "-" version ".tar.gz"))
-       (sha256
-        (base32
-         "0w9yvgrf591phpr1222j0dj7x1n489v2sihnr8syz8xn3aamih6b"))))
-    (build-system cargo-build-system)
-    (arguments
-     `(#:skip-build? #t
-       #:cargo-inputs
-       (("rust-pnacl-build-helper" ,rust-pnacl-build-helper-1.4))))
-    (home-page "https://github.com/DiamondLovesYou/libressl-pnacl-sys")
-    (synopsis "Openssl linking provider for PNaCl/NaCl targets")
-    (description
-     "This package provides an openssl linking provider for PNaCl/NaCl targets.")
-    (license license:expat)))
-
 (define-public rust-libssh2-sys-0.2
   (package
     (name "rust-libssh2-sys")