Update Dockerfile

Dockerfile

@@ -40,8 +40,9 @@ RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
 RUN mkdir /papermc /backup /web
 
 #sets permission for the cronjobs
-RUN chmod 0644 /etc/cron.d/backup
+RUN chmod 0600 /etc/cron.d/backup
 #starts the service for cron
+RUN crontab /etc/cron.d/backup
 
 
 # Add papermc user and group, then change ownership of /papermc and /backup to this user