Set blank results when a non-autocomplete metatag is used

-Otherwise, the last valid autocomplete result will remain
--Causes incorrect results on Tab/Enter completion
-This clears the autocomplete results instead

app/assets/javascripts/autocomplete.js.erb

@@ -167,6 +167,7 @@
         <% TagCategory.short_name_list.each do |category| %>
           case "<%= category %>tags":
         <% end %>
+          resp([]);
           return;
 
         case "order":