Bug 7371: Add 'cardnumber' as option for AutoEmailPrimaryAddress

Bug 7371: Add 'cardnumber' as option for AutoEmailPrimaryAddress

The systempref.sql file had one more option 'cardnumber' that was not
visible from the system preference editor. This patch adds the setting.

To test:
- Check new setting cardnumber is available for AutoEmailPrimaryAddress
- Use setting with a patron that has an email address as cardnumber and
verify email is sent out correctly.

Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>