Fix project buttons layout

theme/templates/projects.html

@@ -18,7 +18,9 @@
       {{ article.content }}
     </div>
   </section>
-  <div class="container text-center">
+  {% if article.download_link or aricle.repo %}
+    <section class="text-center">
+      <div class="container">
         <div class="btn-group">
           {% if article.download_link %}
             <a class="btn btn-primary btn-xl" href="{{ article.download_link }}">Download {{ article.title }}</a>
@@ -29,4 +31,6 @@
           {% endif %}
         </div>
       </div>
+    </section>
+  {% endif %}
 {% endblock %}