Bug 32260: Patron autocomplete - Do not display an alert if request is rejected

Bug 32260: Patron autocomplete - Do not display an alert if request is rejected

Not sure what is going on exactly, neither if this patch is the correct
way to fix this.
The request is "rejected" at some point (by the browser?), when we
search for patrons using the autocomplete and DT "at the same time".

To recreate:
Don't apply this patch
Go to /cgi-bin/koha/reserve/request.pl?biblionumber=1&borrowernumber=5
Search for "edn" then hit enter
You may see an alert, that will disappear
If you don't see the alert, repeat

This patch suggests to ignore the alert if the status of the request is
"rejected".

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>