Bug 19440: Existing calls need to be done in scalar context

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

catalogue/detail.pl

@@ -436,7 +436,7 @@ if (C4::Context->preference("virtualshelves") ) {
 if (C4::Context->preference("FRBRizeEditions")==1) {
     eval {
         $template->param(
-            XISBNS => get_xisbns($isbn)
+            XISBNS => scalar get_xisbns($isbn)
         );
     };
     if ($@) { warn "XISBN Failed $@"; }

opac/opac-detail.pl

@@ -893,7 +893,7 @@ if (C4::Context->preference("virtualshelves") ) {
 if (C4::Context->preference("OPACFRBRizeEditions")==1) {
     eval {
         $template->param(
-            XISBNS => get_xisbns($isbn)
+            XISBNS => scalar get_xisbns($isbn)
         );
     };
     if ($@) { warn "XISBN Failed $@"; }