whois: remove options

Formula/whois.rb

@@ -3,6 +3,7 @@ class Whois < Formula
   homepage "https://packages.debian.org/sid/whois"
   url "https://deb.debian.org/debian/pool/main/w/whois/whois_5.4.0.tar.xz"
   sha256 "3775ae0cfaa6dd8d886e5233c4826225cddcb88c99c2a08130d14e15fe58e378"
+  revision 1
   head "https://github.com/rfc1036/whois.git"
 
   bottle do
@@ -12,10 +13,8 @@ class Whois < Formula
     sha256 "69e7f9739c62cd476b297cfa2263be993970f4646d925db6e35c2b74fce76948" => :sierra
   end
 
-  option "with-libidn2", "Compile with IDN support"
-
-  depends_on "libidn2" => :optional
-  depends_on "pkg-config" => :build if build.with? "libidn2"
+  depends_on "pkg-config" => :build
+  depends_on "libidn2"
 
   def install
     ENV.append "LDFLAGS", "-L/usr/lib -liconv"