[theme] peel out oscar from SearXNG development

This is the first step of removing oscar theme

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searx/templates/oscar/messages/no_cookies.html

@@ -1,5 +0,0 @@
-{% from 'oscar/macros.html' import icon %}
-<div class="alert alert-info fade in" role="alert">
-    <strong class="lead">{{ icon('info-sign') }} {{ _('Information!') }}</strong>
-    {{ _('currently, there are no cookies defined.') }}
-</div>