If the Nextcloud container is recreated while the cronjob container is still running, the ID of the
container is obtained each time the cron tasks are executed. Previously it was cached on entrypoint,
so if the ID changed this container would fail.
New NEXTCLOUD_EXEC_USER environment variable added which allows control over which
user is used to execute cron tasks inside the Nextcloud container. By default, the
user is `www-data`. If the environment variable is specified but empty, no `--user`
option is provided to `docker exec`.
Mount individual shell scripts (with the `*.sh` extension) inside `/cron-scripts/` in the
container. The cron daemon will automatically run these scripts inside the Nextcloud
container for you. Write the scripts as if they will run in the Nextcloud container
itself.
