fix tijdschriften return

Author: JorisLambrechts

themes/default/view/omeka/site/item/show.phtml

@@ -14,7 +14,7 @@ $type_array = [
   "Agendapunt" => "agenda",
   "Film" => "films",
   "Filmkopie" => "filmkopies",
-  "Ledenblad" => "tijdschriften"  
+  "Ledenblad" => "ledenbladen",  
 ];