Bug 19259: Enforce type of the delay value when editing overdue rules - template...

Bug 19259: Enforce type of the delay value when editing overdue rules - template side only

Overdue rules do not save when a delay that is not an integer > 0,
without any warnings.
This patch forces the user to select a number > 0.

Test plan:
Without this patch applied, enter non-integer value or negative or 0
=> The rule will not be inserted without any warnings.
With this patch applied you will get an message from the browser and the
form will not save

Signed-off-by: David Bourgault <david.bourgault@inlibro.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>