Use smaller heading size for Uploads

Because it’s a top-level page without a back link it should have a
smaller heading size.

app/templates/views/jobs/jobs.html

@@ -7,7 +7,7 @@
 {% endblock %}
 
 {% block maincolumn_content %}
-    <h1 class="heading-large">Uploads</h1>
+    <h1 class="heading-medium">Uploads</h1>
     <div class="dashboard">
       {% if show_scheduled_jobs %}
         {% with hide_heading = True %}