Bug 31041: Prevent duplicate display of cashup summary when printing

Bug 31041: Prevent duplicate display of cashup summary when printing

To test:
1. Have POS on.
2. Have some registers and items for sale. Make some sales to 'Cashup'.
3. If you have enough enough lines in the table so that 'register.pl' would print on 2 or more pages, the summary will be duplicated that same number of time.

If you are lazy like me and don't want to make that many transaction you can also add some content to the page like this:

for (let i = 0; i < 100; i++) {
  $('#register').append('<h1>TEST</h1>');
}

4. APPLY PATCH, clear browser cahche
5. Try printing again, you should only get one cashup summary when printing.

Signed-off-by: Juliet Heltibridle <jheltibridle@rcplib.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit 85fb62f3d6e0784bf75309325b78712f18877055)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
(cherry picked from commit d74cec96120cec3ea6bec79006c371e4794cb3da)
Signed-off-by: Pedro Amorim <pedro.amorim@ptfs-europe.com>