fix: Mark more configs as sensitive

Signed-off-by: Joas Schilling <coding@schilljs.com>

lib/private/SystemConfig.php

@@ -42,6 +42,7 @@ class SystemConfig {
 		'dbhost' => true,
 		'dbpassword' => true,
 		'dbuser' => true,
+		'dbreplica' => true,
 		'activity_dbname' => true,
 		'activity_dbhost' => true,
 		'activity_dbpassword' => true,
@@ -57,6 +58,7 @@ class SystemConfig {
 		'updater.server.url' => true,
 		'trusted_proxies' => true,
 		'preview_imaginary_url' => true,
+		'preview_imaginary_key' => true,
 		'proxyuserpwd' => true,
 		'sentry.dsn' => true,
 		'sentry.public-dsn' => true,