Fixed not loading disqus if it is not configured

_includes/comments.html

@@ -4,11 +4,13 @@
 	/* * * CONFIGURATION VARIABLES: EDIT BEFORE PASTING INTO YOUR WEBPAGE * * */
 	var disqus_shortname = '{{ site.owner.disqus-shortname }}';
 
+	if ((disqus_shortname || '') != '') {
 		/* * * DON'T EDIT BELOW THIS LINE * * */
 		(function() {
 			var dsq = document.createElement('script'); dsq.type = 'text/javascript'; dsq.async = true;
 			dsq.src = '//' + disqus_shortname + '.disqus.com/embed.js';
 			(document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(dsq);
 		})();
+	}
 </script>
 <noscript>Please enable JavaScript to view the <a href="http://disqus.com/?ref_noscript">comments powered by Disqus.</a></noscript>