Nextcloud cronjobs are not running

From the logs of one (apparently any) nextcloud-cron job:

# kubectl logs -n stackspin-apps job/nc-nextcloud-cron-27445905
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100    77  100    77    0     0     14      0  0:00:05  0:00:05 --:--:--    16
{"data":{"message":"Backgroundjobs are using system cron!"},"status":"error"}

And indeed, nextcloud is set to use the "cron" for cronjobs, not Webcron which I assume is what we need to call the cronjob the way we try to. Changing that setting to "Webcron" in the nextcloud web interface makes the error go away.

We should change this line to the value webcron instead of cron.

Also, the kubernetes cronjob should really fail in a case such as this. We should refine the script that curls nextcloud to check for errors and return the proper exit code.