jbigkit: make universal optional

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Formula/jbigkit.rb

@@ -5,12 +5,13 @@ class Jbigkit < Formula
   url 'http://www.cl.cam.ac.uk/~mgk25/download/jbigkit-2.0.tar.gz'
   sha1 'cfb7d3121f02a74bfb229217858a0d149b6589ef'
 
+  option :universal
   option 'with-check', "Verify the library during install"
 
   def install
     # Set for a universal build and patch the Makefile.
     # There's no configure. It creates a static lib.
-    ENV.universal_binary
+    ENV.universal_binary if build.universal?
     system "make", "CC=#{ENV.cc}", "CCFLAGS=#{ENV.cflags}"
 
     # It needs j1 to make the tests happen in sequence.