Bug 33478: Apply formatting to OVERDUES_SLIP

To test:

1. Check out an item to a user. Set the due date to a time in the past so it is overdue
2. Click Print in the members toolbar, then Print overdues
3. Confirm your format settings for OVERDUES_SLIP are applied

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>

members/print_overdues.pl

@@ -67,6 +67,7 @@ $template->param(
     title          => $letter->{name},
     plain          => !$letter->{is_html},
     borrowernumber => $borrowernumber,
+    style          => $letter->{style},
 );
 
 output_html_with_http_headers $input, $cookie, $template->output;