Display the instance admin on the welcome page

calsocial/templates/_macros.html

@@ -25,6 +25,6 @@
     <img src="{{ url_for('static', filename='avatars/' + profile.builtin_avatar + '.svg') }}" alt="" class="ui circular avatar image">
     {% endif %}
     <div class="display name">{{ profile.display_name }}</div>
-    <div class="handle">{{ profile }}</div>
+    <div class="handle">{{ profile or '' }}</div>
 </a>
 {% endmacro %}