Configure trusted proxies when required

templates/config.php.jinja2

@@ -9,6 +9,11 @@ $CONFIG = array (
   'trusted_domains' => array(
     0 => '{{ nextcloud.domain }}',
   ),
+{% if default_proxy is defined and default_proxy %}
+  'trusted_proxies' => array(
+    0 => '{{ hostvars[default_proxy]['proxy_address'] }}',
+  ),
+{% endif %}
   'datadirectory' => '{{ dataRoot }}',
   'dbtype' => 'mysql',
   'version' => '{{ nextcloud_current_version.stdout }}',