ghostscript: add --without-x

gs-9.06 is designed to build with only `:libpng` these days, but it
fails to compile with superenv unless we specify that we don't
want to build with X11.

* Remove the `ENV['LIBS'] = some/X11/path`
* Add `--without-x` to fix a build error.

Fixes Homebrew/homebrew#14564

Closes Homebrew/homebrew#14596.

Signed-off-by: Misty De Meo <mistydemeo@gmail.com>

Formula/ghostscript.rb

@@ -43,8 +43,6 @@ class Ghostscript < Formula
 
   def install
     ENV.deparallelize
-    # ghostscript configure ignores LDFLAGs apparently
-    ENV['LIBS'] = "-L#{MacOS::X11.lib}" if MacOS::X11.installed?
 
     src_dir = build.head? ? "gs" : "."
 
@@ -56,6 +54,7 @@ class Ghostscript < Formula
         --disable-compile-inits
         --disable-gtk
         --with-system-libtiff
+        --without-x
       ]
 
       if build.head?