Revert "use else is more elegant"

This reverts commit c563745.

dojo_theme/templates/components/navbar.html

@@ -30,7 +30,7 @@
         {{ navitem("管理面板", url_for("admin.view"), "fa-wrench") }}
         {% endif %}
 
-        {% else %}
+        {% if not is_admin() %}
         {{ navitem("简介", url_for("pwncollege_users.view_self"), "fa-user-circle") }}
         {% endif %}
         {{ navitem("设置", url_for("views.settings"), "fa-cogs") }}