freebsd: hide Vagrantfile from guest

Author: Mizux

ci/vagrant/freebsd/Vagrantfile

@@ -56,7 +56,7 @@ Vagrant.configure("2") do |config|
   # by making sure your Vagrantfile isn't accessible to the vagrant box.
   # If you use this you may want to enable additional shared subfolders as
   # shown above.
-  # config.vm.synced_folder ".", "/vagrant", disabled: true
+  config.vm.synced_folder ".", "/vagrant", disabled: true
 
   # Provider-specific configuration so you can fine-tune various
   # backing providers for Vagrant. These expose provider-specific options.