Bug 24268: Break assignment and warn into separate actions

Signed-off-by: Liz Rea <wizzyrea@gmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>

misc/cronjobs/advance_notices.pl

@@ -582,7 +582,11 @@ sub send_digests {
                     branchcode     => $branchcode,
                     message_transport_type => $transport
                 }
-            ) || warn "no letter of type '$params->{letter_type}' found for borrowernumber $borrowernumber. Please see sample_notices.sql";
+            );
+            unless ( $letter ){
+                warn "no letter of type '$params->{letter_type}' found for borrowernumber $borrowernumber. Please see sample_notices.sql";
+                next;
+            }
             push @letters, $letter if $letter;
         }