Simplify code, we already have the query string generated

Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/html/trans/change_list.html

@@ -10,7 +10,7 @@
 
 <ul class="pagination pull-right flip">
 <li>
-<a href="{% url 'changes-csv' %}?{{ request.GET.urlencode }}" title="{% trans "Download all changes as CSV" %}"><i class="fa fa-download"></i></a>
+<a href="{% url 'changes-csv' %}?{{ query_string }}" title="{% trans "Download all changes as CSV" %}"><i class="fa fa-download"></i></a>
 </li>
 {% if changes_rss %}
 <li>