gnu: curl: Restore derivation.

Commit af8f7eb4f2 accidentally changed the cURL
derivation.  Remove use of HIDDEN-PACKAGE and restore input order to prevent a
large number of rebuilds.

* gnu/packages/ssh.scm (libssh2-1.8.0): Move from here ...
* gnu/packages/curl.scm (libssh2-1.8.0): ... to here.  Don't use
HIDDEN-PACKAGE and make it non-public.
(curl)[inputs]: Move LIBSSH2-1.8.0 where it was before af8f7eb4f2.

gnu/packages/curl.scm

@@ -48,6 +48,23 @@
   #:use-module (gnu packages tls)
   #:use-module (gnu packages web))
 
+;; XXX A hidden special obsolete libssh2 for temporary use in the curl package.
+;; <https://bugs.gnu.org/34927>
+(define libssh2-1.8.0
+  (package
+    (inherit libssh2)
+    (version "1.8.0")
+    (source (origin
+              (method url-fetch)
+              (uri (string-append
+                    "https://www.libssh2.org/download/libssh2-"
+                    version ".tar.gz"))
+               (sha256
+                (base32
+                 "1m3n8spv79qhjq4yi0wgly5s5rc8783jb1pyra9bkx1md0plxwrr"))
+               (patches
+                (search-patches "libssh2-fix-build-failure-with-gcrypt.patch"))))))
+
 (define-public curl
   (package
    (name "curl")
@@ -66,14 +83,14 @@
    (inputs `(("gnutls" ,gnutls)
              ("gss" ,gss)
              ("libidn" ,libidn)
-             ("openldap" ,openldap)
-             ("nghttp2" ,nghttp2 "lib")
-             ("zlib" ,zlib)
              ;; TODO XXX <https://bugs.gnu.org/34927>
              ;; Curl doesn't actually use or refer to libssh2 because the build
              ;; is not configured with '--with-libssh2'.  Remove this input when
              ;; a mass rebuild is appropriate (e.g. core-updates).
-             ("libssh2" ,libssh2-1.8.0)))
+             ("libssh2" ,libssh2-1.8.0)
+             ("openldap" ,openldap)
+             ("nghttp2" ,nghttp2 "lib")
+             ("zlib" ,zlib)))
    (native-inputs
      `(("perl" ,perl)
        ;; to enable the --manual option and make test 1026 pass

gnu/packages/ssh.scm

@@ -143,24 +143,6 @@ a server that supports the SSH-2 protocol.")
    (license license:bsd-3)
    (home-page "https://www.libssh2.org/")))
 
-;; XXX A hidden special obsolete libssh2 for temporary use in the curl package.
-;; <https://bugs.gnu.org/34927>
-(define-public libssh2-1.8.0
-  (hidden-package
-    (package
-      (inherit libssh2)
-      (version "1.8.0")
-      (source (origin
-               (method url-fetch)
-               (uri (string-append
-                      "https://www.libssh2.org/download/libssh2-"
-                      version ".tar.gz"))
-               (sha256
-                (base32
-                 "1m3n8spv79qhjq4yi0wgly5s5rc8783jb1pyra9bkx1md0plxwrr"))
-               (patches
-                (search-patches "libssh2-fix-build-failure-with-gcrypt.patch")))))))
-
 (define-public openssh
   (package
    (name "openssh")