gettext: add acl dependency

Author: cho-m

Formula/g/gettext.rb

@@ -18,9 +18,14 @@ class Gettext < Formula
   end
 
   depends_on "libunistring"
+
   uses_from_macos "libxml2"
   uses_from_macos "ncurses"
 
+  on_linux do
+    depends_on "acl"
+  end
+
   def install
     args = [
       "--with-libunistring-prefix=#{Formula["libunistring"].opt_prefix}",