OLD_BINSTUB should remain the same

Author: mrbrdo

Diff for: lib/spring/client/binstub.rb

@@ -44,7 +44,7 @@ class Binstub < Command
 end
 CODE
 
-      OLD_BINSTUB = %{if Gem::Specification.find_all_by_name("spring").empty?}
+      OLD_BINSTUB = %{if !Process.respond_to?(:fork) || Gem::Specification.find_all_by_name("spring").empty?}
 
       class Item
         attr_reader :command, :existing