{% load i18n lib_tags %}{% load url from future %}
<h2>{% trans "Profile" %} <small>{% trans "Update your personal information" %}</small></h2>
<hr>
<form class="form-horizontal" method="POST" action="{% url 'modoboa.core.views.user.profile' %}" 
      id="uprefs_form">{% csrf_token %}
  {% render_form form %}
  <div class="form-actions">
    <button type="submit" class="btn btn-primary" id="update" name="update">{% trans 'Update' %}</button>
  </div>
</form>

{% load i18n lib_tags %}{% load url from future %}
<h2>{% trans "Profile" %} <small>{% trans "Update your personal information" %}</small></h2>
<hr>
<form class="form-horizontal" method="POST" action="{% url 'modoboa.core.views.user.profile' %}" 
      id="uprefs_form">{% csrf_token %}
  {% render_form form %}
  <div class="form-actions col-lg-3  col-md-2 col-sm-3 col-lg-offset-9  col-md-offset-9 col-sm-offset-9 pull-right">
    <button type="submit" class="btn btn-primary" id="update" name="update">{% trans 'Update' %}</button>
  </div>
  </div>
</form>

Change display of update button
Change display of update button
