Fix some issues with NFS version selecting

config/default.rb

@@ -26,7 +26,6 @@ Vagrant::Config.run do |config|
 
   config.nfs.map_uid = :auto
   config.nfs.map_gid = :auto
-  config.nfs.version = 3
 
   config.package.name = 'package.box'
 end

lib/vagrant/action/vm/nfs.rb

@@ -91,6 +91,7 @@ module Vagrant
             key, opts = data
             opts[:map_uid] = prepare_permission(:uid, opts)
             opts[:map_gid] = prepare_permission(:gid, opts)
+            opts[:version] ||= 3
 
             acc[key] = opts
             acc

lib/vagrant/config/nfs.rb

@@ -3,7 +3,6 @@ module Vagrant
     class NFSConfig < Base
       attr_accessor :map_uid
       attr_accessor :map_gid
-      attr_accessor :version
     end
   end
 end