Call I18n reload after adding value to path

Otherwise, the translations still won't be available. See https://github.com/dotless-de/vagrant-vbguest/issues/107 for a discussion around a similar issue in an unrelated plugin. I noticed this issue when I had a bad configuration and started getting error messages like this.

````
[reidmv@pseudonix007:~/vagrant/seteam/] % vagrant provision centos64d --provision-with pe_bootstrap
[centos64d] Running provisioner: pe_bootstrap...
translation missing: en.pebuild.transfer.open_uri.download_failed
````