Change wp-cron to a PHP CLI command instead of curling (which gets blocked by our security rules)

[poespas]

Closes #353

[Brada-Groep]

I'd recommend adding the fact that the wp-cron.php doesn't work by default on Hypernode in the text so that when someone is googling that, he'll get recommended this article and know why his cron job isn't working.

Current first alinea

In this guide, we'll explain how to replace the default WordPress cron job with a cron job on your Hypernode server. This can be useful for low traffic sites, important tasks that need to be run at specific times, mitigating excessive DDoS attacks, or improving high page load times.

Proposed first alinea

In this guide, we'll explain how to replace the default WordPress cron job with a cron job on your Hypernode server. This can be useful for low-traffic sites, important tasks that need to be run at specific times, mitigating excessive DDoS attacks, or improving high page load times. This will also enable the wp-cron.php to run when it is blocked by the webserver (which is the default behaviour of a Hypernode).