No need to use GOOGLE_ANALYTICS_SITE_URL in Universal Analytics code

According to
[documentation](https://developers.google.com/analytics/devguides/collection/analyticsjs/method-reference#create)
third parameter is optional.

templates/_includes/analytics.html

@@ -1,24 +1,11 @@
 {% if GOOGLE_ANALYTICS %}
-    {% if GOOGLE_ANALYTICS_SITE_URL %}
-        <script>
-            (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
-             (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
-             m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
-             })(window,document,'script','//www.google-analytics.com/analytics.js','ga');
-            ga('create', '{{GOOGLE_ANALYTICS}}', '{{GOOGLE_ANALYTICS_SITE_URL}}');
-            ga('send', 'pageview');
-        </script>
-    {% else %}
-        <script type="text/javascript">
-            var _gaq = _gaq || [];
-            _gaq.push(['_setAccount', '{{GOOGLE_ANALYTICS}}']);
-            _gaq.push(['_trackPageview']);
-            (function() {
-                var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
-                ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
-                var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
-            })();
-        </script>
-    {% endif %}
+<script>
+    (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
+     (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
+     m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
+     })(window,document,'script','//www.google-analytics.com/analytics.js','ga');
+    ga('create', '{{GOOGLE_ANALYTICS}}', 'auto');
+    ga('send', 'pageview');
+</script>
 {% endif %}