Bug 14045: Introduce the maxonsiteissueqty field as a copy of maxissueqty

Bug 14045: Introduce the maxonsiteissueqty field as a copy of maxissueqty

This patch adds the new fields maxonsiteissueqty as a copy of the
existing maxissueqty field.

There is no brainy code here, it only adds the ability to fill the new
field from the admin interface (admin/smart-rules.pl).

Signed-off-by: Nicolas Legrand <nicolas.legrand@bulac.fr>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>