Fix strict-mode in tour

Change-Id: Ifeaa1c32ad5d47fc4be4095113a0db70bcbf3a72
diff --git a/dev/js/src/tour/tours.js b/dev/js/src/tour/tours.js
index 4193f28..d67b518 100644
--- a/dev/js/src/tour/tours.js
+++ b/dev/js/src/tour/tours.js
@@ -171,8 +171,8 @@
             targetedElement.value = loc.TOUR_Qexample;
           break;
         case "vc-view":  
-          vchoo = doe.querySelector("#vc-choose");
-          vcv = doe.querySelector("#vc-view");  
+          let vchoo = doe.querySelector("#vc-choose");
+          let vcv = doe.querySelector("#vc-view");  
           KorAP._delete.apply(KorAP.vc.root());
     
           KorAP.vc.fromJson(loc.TOUR_vcQuery);