Bug 7267: Add account number to French PDF template

To test:
- Switch system preference OrderPdfFormat to pdfformat::layout3pagesfr
- Create one or more baskets with some orders each.
- Add all baskets to one basket group
- Print the basket group
- Check the account number from your vendor shows up with the other
  vendor details

Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>

acqui/pdfformat/layout3pagesfr.pm

@@ -380,6 +380,8 @@ sub printhead {
     $text->text($bookseller->{address2});
     $text->translate(100/mm,  ($height-200)/mm);
     $text->text($bookseller->{address3});
+    $text->translate(100/mm, ($height-205)/mm);
+    $text->text($bookseller->{accountnumber});
 
     # print delivery infos
     $text->font( $pdf->corefont("Times-Bold", -encoding => "utf8"), 4/mm );