Fix regression

* fixes #18529

core/js/config.php

@@ -62,7 +62,7 @@ if ($defaultExpireDateEnabled) {
 $outgoingServer2serverShareEnabled = $config->getAppValue('files_sharing', 'outgoing_server2server_share_enabled', 'yes') === 'yes';
 
 $array = array(
-	"oc_debug" => $config->getSystemValue('debug', false),
+	"oc_debug" => $config->getSystemValue('debug', false) ? 'true' : 'false',
 	"oc_isadmin" => OC_User::isAdminUser(OC_User::getUser()) ? 'true' : 'false',
 	"oc_webroot" => "\"".OC::$WEBROOT."\"",
 	"oc_appswebroots" =>  str_replace('\\/', '/', json_encode($apps_paths)), // Ugly unescape slashes waiting for better solution