Update favicon and bust cache (#6435)

* Update favicon and bust cache

* Use existing cache-busting mechanism

src/olympia/amo/templates/amo/404-responsive.html

@@ -8,7 +8,7 @@
     {% endif %}
     <title>{% block title %}{{ _('Page Not Found') }}{% endblock %}</title>
     <link rel="shortcut icon" type="image/x-icon"
-          href="{{ STATIC_URL }}img/favicon.ico">
+          href="{{ static('img/favicon.ico') }}">
     {% block site_css %}
       {{ css('errors/css') }}
     {% endblock %}

src/olympia/devhub/templates/devhub/index.html

@@ -13,7 +13,7 @@
     <title>{% block title %}{{ dev_page_title() }}{% endblock %}</title>
 
     <link rel="shortcut icon" type="image/x-icon"
-          href="{{ STATIC_URL }}img/favicon.ico">
+          href="{{ static('img/favicon.ico') }}">
 
     {% block rss_feed %}{% endblock %}
 

src/olympia/templates/base.html

@@ -9,7 +9,7 @@
     <title>{% block title %}{{ _('Mozilla Add-ons') }}{% endblock %}</title>
 
     <link rel="shortcut icon" type="image/x-icon"
-          href="{{ STATIC_URL }}img/favicon.ico">
+          href="{{ static('img/favicon.ico') }}">
 
     {% block rss_feed %}{% endblock %}
 

src/olympia/templates/impala/base.html

@@ -9,7 +9,7 @@
     <title>{% block title %}{{ _('Mozilla Add-ons') }}{% endblock %}</title>
 
     <link rel="shortcut icon" type="image/x-icon"
-          href="{{ STATIC_URL}}img/favicon.ico">
+          href="{{ static('img/favicon.ico') }}">
 
     {% block rss_feed %}{% endblock %}