Fix wording.

templates/integrations/add_pushover.html

@@ -11,7 +11,7 @@
         {% if request.user.is_authenticated %}
         <p>
             <a href="https://www.pushover.net/">Pushover</a> delivers
-            real-time notifications on your Android, iPhone, iPad, and Desktop,
+            real-time notifications on your Android, iPhone, iPad, Desktop,
             Android Wear and Apple Watch. You can set up {% site_name %} to
             receive Pushover notifications in a few simple steps.
         </p>