FIX: archive link not worked if no archive menu.

Issue #1823

Author: ivan-nginx

layout/_macro/sidebar.swig

@@ -42,7 +42,11 @@
 
           {% if config.archive_dir != '/' and site.posts.length > 0 %}
             <div class="site-state-item site-state-posts">
+            {% if theme.menu.archives %}
               <a href="{{ url_for(theme.menu.archives) }}">
+            {% else %}
+              <a href="{{ url_for(config.archive_dir) }}">
+            {% endif %}
                 <span class="site-state-item-count">{{ site.posts.length }}</span>
                 <span class="site-state-item-name">{{ __('state.posts') }}</span>
               </a>