changed class-name for 500-backup_mail

Author: florian030

server/lib/classes/cron.d/500-backup_mail.inc.php

@@ -27,7 +27,7 @@
 EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
-class cronjob_backup extends cronjob {
+class cronjob_backup_mail extends cronjob {
 
 	// job schedule
 	protected $_schedule = '0 0 * * *';