Followup to Bug 4305: multiple ISBNS in biblioitems.isbn breaks patron

This patch adds a scrub for ' | ' when the ISBN comes from the
biblioitems table, in the event that Koha has attempted to store
multiple ISBNs in the field.  The ISBN presented to Business::ISBN will
now be something it can handle.

Signed-off-by: Galen Charlton <gmcharlt@gmail.com>

C4/Koha.pm

@@ -1242,6 +1242,9 @@ sub GetNormalizedISBN {
     my ($isbn,$record,$marcflavour) = @_;
     my @fields;
     if ($isbn) {
+        # Koha attempts to store multiple ISBNs in biblioitems.isbn, separated by " | "
+        # anything after " | " should be removed, along with the delimiter
+        $isbn =~ s/(.*)( \| )(.*)/$1/;
         return _isbn_cleanup($isbn);
     }
     return undef unless $record;