DEV: when synchornizing state pull tags

In some cases we may want topic tracking state to keep track of tags
this small change ensures we do not remove them if they are already in place

app/assets/javascripts/discourse/app/models/topic-tracking-state.js

@@ -354,6 +354,10 @@ const TopicTrackingState = EmberObject.extend({
         row.category_id = topic.category.id;
       }
 
+      if (topic.tags) {
+        row.tags = topic.tags;
+      }
+
       tracker.states["t" + topic.id] = row;
     });