Disable cron.allow

Recently web- and appservers have been updated with an [`/etc/cron.allow` file](https://github.com/ByteInternet/puppet-platform/commit/40305e687bd7a309753af1d6a2d6c4eeb9eba485) that forbids normal users from using the `crontab` command, to prevent puny hackers from adding cronjobs. However, the Cronmanager on the Servicepanel uses `byte-rpc-crontab`, on the web/appservers, running as the customer, to enable or disable Magento cronjobs. And `byte-rpc-crontab` checks `/etc/cron.{allow,deny}`.

This PR disables the check for `/etc/cron.allow` and `/etc/cron.deny` in the already patched version of `byte-rpc-crontab`. If puny hacker finds out about this command, he will be able to add a cronjob to /home/users/crontabs, that will then be executed on the shellservers. C'est la vie.