feat(updater): Disable web based updater for real (nextcloud#2109)

Web based updates aren't used in the image, but the button remains enabled and generates an error when clicked. Let's eliminate the web updater button.

Signed-off-by: Josh Richards <josh.t.richards@gmail.com>

Author: joshtrichards

.config/upgrade-disable-web.config.php

@@ -0,0 +1,4 @@
+<?php
+$CONFIG = array (
+  'upgrade.disable-web' => true,
+);