gnu: optipng: Update to 0.7.7 [security fixes].

This release claims to fix 2 vulnerabilities:
- ‘an integer overflow vulnerability in the TIFF decoder’
  (CVE-2017-1000229, previously patched in Guix), and
- ‘a buffer overflow vulnerability in the GIF decoder’.

* gnu/packages/image.scm (optipng): Update to 0.7.7.
[source]: Remove patch.
[arguments]: Substitute INVOKE for SYSTEM* and end phase with #t.
* gnu/packages/patches/optipng-CVE-2017-1000229.patch: Delete file.
* gnu/local.mk (dist_patch_DATA): Remove it.

gnu/packages/image.scm

@@ -10,7 +10,7 @@
 ;;; Copyright © 2016 Leo Famulari <leo@famulari.name>
 ;;; Copyright © 2016, 2017 Leo Famulari <leo@famulari.name>
 ;;; Copyright © 2016, 2017 Efraim Flashner <efraim@flashner.co.il>
-;;; Copyright © 2016, 2017 Tobias Geerinckx-Rice <me@tobias.gr>
+;;; Copyright © 2016, 2017, 2018 Tobias Geerinckx-Rice <me@tobias.gr>
 ;;; Copyright © 2016 Eric Bavier <bavier@member.fsf.org>
 ;;; Copyright © 2016, 2017 Arun Isaac <arunisaac@systemreboot.net>
 ;;; Copyright © 2016, 2017 Kei Kebreau <kkebreau@posteo.net>
@@ -1091,29 +1091,28 @@ installed as @code{stb_image}.")
 (define-public optipng
   (package
     (name "optipng")
-    (version "0.7.6")
+    (version "0.7.7")
     (source
      (origin
        (method url-fetch)
        (uri (string-append "http://prdownloads.sourceforge.net/optipng/optipng-"
                            version ".tar.gz"))
-       (patches (search-patches "optipng-CVE-2017-1000229.patch"))
        (sha256
         (base32
-         "105yk5qykvhiahzag67gm36s2kplxf6qn5hay02md0nkrcgn6w28"))))
+         "0lj4clb851fzpaq446wgj0sfy922zs5l5misbpwv6w7qrqrz4cjg"))))
     (build-system gnu-build-system)
     (inputs
      `(("zlib" ,zlib)))
     (arguments
      '(#:phases
        (modify-phases %standard-phases
-         ;; configure script does not accept arguments CONFIG_SHELL and SHELL
          (replace 'configure
            (lambda* (#:key outputs #:allow-other-keys)
-             (zero? (system* "sh" "configure"
-                             (string-append "--prefix=" (assoc-ref outputs "out")))))))))
-    (synopsis "Optimizer that recompresses PNG image files to a
-smaller size")
+             ;; configure script doesn't accept arguments CONFIG_SHELL and SHELL
+             (invoke "sh" "configure"
+                     (string-append "--prefix=" (assoc-ref outputs "out")))
+             #t)))))
+    (synopsis "Optimizer that recompresses PNG image files to a smaller size")
     (description "OptiPNG is a PNG optimizer that recompresses image
 files to a smaller size, without losing any information.  This program
 also converts external formats (BMP, GIF, PNM and TIFF) to optimized