Fix session timer to work with format localization

hshassets/templates/hshassets/includes/session_timer.html

 {% load i18n %}
+{% load l10n %}
 
 {% comment %}
 This template can be included in apps that need to handle any kind of custom sessions.
@@ -35,7 +36,7 @@ Also make sure to include the corresponding javascript in your "base.html":
         <div class="navbar-item has-text-grey">
             {% trans "Your session will automatically expire in:" %}
             <span class="icon is-small has-text-left has-text-right"><i class="fa fa-clock-o"></i></span>
-            <span id="session_timer" data-initial-seconds-left="{{ initial_seconds_left }}">00:00</span>
+            <span id="session_timer" data-initial-seconds-left="{{ initial_seconds_left|unlocalize }}">00:00</span>
         </div>
         <a href="{% url "flush-session" %}" class="navbar-item">
             <span class="icon is-small has-text-right"><i class="fa {% if end_session_icon %}{{ end_session_icon }}{% else %}fa-sign-out{% endif %}"></i></span>