FIX: Back button would go to previous topic instead of list

See related topic:
https://meta.discourse.org/t/back-button-history-not-properly-working/122183

The issue here is the transition was not completing properly which meant
if you backed out of a topic quickly and entered a new one, hitting back
in the second topic would sometimes take you to the previous one instead
of back to the topic list.

app/assets/javascripts/discourse/routes/topic-from-params.js.es6

@@ -89,6 +89,10 @@ export default Discourse.Route.extend({
         "previousURL",
         document.location.pathname
       );
+
+      // NOTE: omitting this return can break the back button when transitioning quickly between
+      // topics and the latest page.
+      return true;
     }
   }
 });