[ui] Better naming for leaderboard column on activity page

beat/web/ui/templates/ui/activity_stream.html

@@ -91,7 +91,7 @@
 
   {% if leaderboards and not request.GET.all %}
   <div class="col-sm-5">
-    <h3>Latest Leaderboard Changes</h3>
+    <h3>Latest Leaderboard Updates</h3>
     <p class="help">From subscribed leaderboards only. Click <a href="{% url "search:list" author.username %}">here</a> to see more</p>
     <hr/>