Deprecate the animated_favicon variable

APNG seems to be well supported so it's not needed I guess

templates/page.html

@@ -1,7 +1,7 @@
 {% extends "base.html" %}
 
 {% block content %}
-{% if page.extra.archive %}
+{%- if page.extra.archive -%}
 	<div class="statement-container archive">
 		<strong class="big">
 			<i class="icon"></i>
@@ -9,6 +9,6 @@
 		</strong>
 		{{ page.extra.archive | markdown | safe }}
 	</div>
-{% endif %}
+{%- endif -%}
 {{ page.content | safe }}
 {% endblock content %}