disabled 'firefox required' balloon messages from apps/ by overriding them with an empty 'balloon' block (bug 693713)

apps/webapps/templates/webapps/base.html

@@ -11,6 +11,8 @@
 
 {% block aux_nav %}{% endblock %}
 
+{% block balloons %}{% endblock %}
+
 {% block footer %}
   {% include "amo_footer_small.html" %}
 {% endblock %}

templates/impala/base.html

@@ -87,6 +87,7 @@
             {{ site_nav() }}
             {% endblock %}
           </div>
+          {% block balloons %}
           {% if ADMIN_MESSAGE or settings.READ_ONLY %}
             <div class="site-balloon" id="site-notice">
               {% if ADMIN_MESSAGE %}
@@ -147,6 +148,7 @@
             </p>
             <a href="#" class="close">{{ _('Close') }}</a>
           </div>
+          {% endblock %}
         </div>
       {% endblock site_header %}