remove unnecessary margin

src/server/views/layout/layout.html

@@ -114,7 +114,7 @@
     </ul>
 
     <!-- 5 user action -->
-    <ul class="navbar-nav mr-2">
+    <ul class="navbar-nav">
       {% if user and user.admin %}
       <li class="nav-item">
         <a class="nav-link" href="/admin">