/etc/cron.d/mystamps-backup-remote: hide credentials

[php-coder]

We need to find a way of hiding credentials (for webdav and gpg). Currently they're present in /etc/cron.d/mystamps-backup-remote and, the most dangerous, they're appears in the cron reports.

Also don't forget to change passwords or cleanup /var/log/syslog after hiding credentials.

Tech debt for: a0fea08 (#418)

[php-coder]

Also don't forget to change passwords or cleanup /var/log/syslog after hiding credentials.

Log files were wiped.