fix the lab from lab_display_name

fix for Rating of a lab is not shown at all.
(#522)

lab_build/page-templates/navbar.handlebars

@@ -1,7 +1,7 @@
 <ul class="navbar-nav ml-auto text-center d-flex flex-md-row">
     <li class="vl-rating-display">
         <rating-display spreadsheetid="1x12nhpp0QvnsA6x-O1sV4IA9SAbfVsq_wiexWkutOmU" sheetname="Lab-Clean"
-            columnname="Lab Name" columnvalue="{{lab_display_name}}"
+            columnname="Lab Name" columnvalue="{{lab}}"
             imagesdirectory="https://virtual-labs.github.io/svc-rating/"></rating-display>
     </li>
     <li class="nav-item px-2 m-1">