gnu: gdk-pixbuf: Enable jasper support.

* gnu/packages/gtk.scm (gdk-pixbuf) [arguments]<#:configure-flags>[-Djasper]: New flag.
[inputs]: Add jasper.

Signed-off-by: Léo Le Bouter <lle-bout@zaclys.net>

gnu/packages/gtk.scm

@@ -593,7 +593,7 @@ highlighting and other features typical of a source code editor.")
     (arguments
      `(#:meson ,meson-0.55
        #:glib-or-gtk? #t ; To wrap binaries and/or compile schemas
-       #:configure-flags '("-Dinstalled_tests=false")
+       #:configure-flags '("-Dinstalled_tests=false" "-Djasper=true")
        #:phases
        (modify-phases %standard-phases
          ;; The slow tests take longer than the specified timeout.
@@ -611,7 +611,8 @@ highlighting and other features typical of a source code editor.")
        ;; Used for testing and required at runtime.
        ("shared-mime-info" ,shared-mime-info)))
     (inputs
-     `(("libjpeg" ,libjpeg-turbo)
+     `(("jasper" ,jasper)
+       ("libjpeg" ,libjpeg-turbo)
        ("libpng"  ,libpng)
        ("libtiff" ,libtiff)))
     (native-inputs