Delist Least Authority S4 (#1434)

* cloud-storage.html: delist Least Authority S4

* assets: remove S4.png

_includes/sections/cloud-storage.html

@@ -22,18 +22,6 @@ fdroid="https://f-droid.org/packages/com.nextcloud.client/"
 googleplay="https://play.google.com/store/apps/details?id=com.nextcloud.client"
 %}
 
-{% include cardv2.html
-title="Least Authority S4 - For Experts"
-image="/assets/img/provider/S4.png"
-description="S4 (Simple Secure Storage Service) is Least Authority's verifiably secure off-site backup system for individuals and businesses. 100% client-side encryption and open source transparency. 250GB for $9.95/month or 5TB for $25.95/month. Servers are hosted with Amazon S3 in the US."
-website="https://leastauthority.com/"
-forum="https://forum.privacytools.io/t/discussion-least-authority-s4/288"
-github="https://github.com/LeastAuthority"
-windows="https://github.com/gridsync/gridsync#installation-and-running"
-mac="https://github.com/gridsync/gridsync#installation-and-running"
-linux="https://github.com/gridsync/gridsync#installation-and-running"
-%}
-
 
 <h3>Worth Mentioning</h3>