pygtk: audit fixes

Closes Homebrew/homebrew#49121.

Signed-off-by: Dominyk Tiller <dominyktiller@gmail.com>

Formula/pygtk.rb

@@ -13,6 +13,8 @@ class Pygtk < Formula
     sha256 "760447005d79b08046da88b23a9af552bf1a9d039de8a38401e22ef8ed743f49" => :mountain_lion
   end
 
+  option :universal
+
   depends_on "pkg-config" => :build
   depends_on "glib"
   depends_on "gtk+"
@@ -21,8 +23,6 @@ class Pygtk < Formula
   depends_on "py2cairo"
   depends_on "libglade" => :optional
 
-  option :universal
-
   def install
     ENV.append "CFLAGS", "-ObjC"
     ENV.universal_binary if build.universal?