using isset()

using isset() instead of array_key_exists()

lib/private/AppConfig.php

@@ -288,7 +288,7 @@ class AppConfig implements IAppConfig {
 	public function getFilteredValues($app) {
 		$values = $this->getValues($app, false);
 
-		if (array_key_exists($app, $this->sensitiveValues)) {
+		if (isset($this->sensitiveValues[$app])) {
 			foreach ($this->sensitiveValues[$app] as $sensitiveKey) {
 				if (isset($values[$sensitiveKey])) {
 					$values[$sensitiveKey] = IConfig::SENSITIVE_VALUE;