remove hard coded site url

templates/tag_index.html

@@ -1,10 +1,10 @@
 {% extends "entry_index.html" %}
 {% block page_title %}tag: {{tag.name}} {% endblock %}
 {% block head_feed_link %}/tags/{{tag.slug}}/atom.xml{% endblock %}
-{% block head_feed_title %}tagged: {{tag.name}} » mirnazim.org {% endblock %}
+{% block head_feed_title %}tagged: {{tag.name}} » {{ site_url }} {% endblock %}
 {% block header %}
 {% if tag.name %}
-<h1 class="tag_name"> 
+<h1 class="tag_name">
 tag: {{ tag.name }}<sup>[<a class="tag_feed_icon" title="Atom feed for {{tag.name}} tag" href="/tags/{{ tag.slug }}/atom.xml">atom feeds</a>]</sup>
 </h1>
 {% endif %}