fix event margin

templates/default/activity/event/torrent/download/file/add.html.twig

@@ -3,7 +3,7 @@
         <a href="{{ path('user_info', { userId : user.id }) }}">
             <img class="border-radius-50 border-color-default vertical-align-middle" src="{{ user.identicon }}" alt="{{ 'identicon' | trans }}" />
         </a>
-        <span class="margin-x-4-px">
+        <span class="margin-l-4-px">
             {{ 'have downloaded torrent file' | trans }}
         </span>
         {% if session.user.moderator or session.user.owner %}