core: put the AE logo in the CSS

Signed-off-by: Skia <skia@libskia.so>

core/templates/core/base.jinja

@@ -16,8 +16,7 @@
     <body>
         {% block header %}
         {% if not popup %}
-        <div id="logo"><a href="{{ url('core:index') }}"><img src="{{ static('core/img/logo.png') }}"
-                                                              alt="{% trans %}Logo{% endtrans %}" /></a></div>
+        <div id="logo" style="background-image: url('{{ static('core/img/logo.png') }}');"><a href="{{ url('core:index') }}"></a></div>
         {% set sith = get_sith() %}
         {% if sith.alert_msg %}
         <div id="alert_box">