Use less deprecated methods in base.php

Signed-off-by: Louis Chemineau <louis@chmn.me>

Author: artonge

lib/base.php

@@ -365,10 +365,7 @@ private static function printUpgradePage(\OC\SystemConfig $systemConfig) {
 
 		$oldTheme = $systemConfig->getValue('theme');
 		$systemConfig->setValue('theme', '');
-		OC_Util::addScript('core', 'common');
-		OC_Util::addScript('core', 'main');
-		OC_Util::addTranslations('core');
-		OC_Util::addScript('update', null, 'core');
+		\OCP\Util::addScript('update', null, 'core');
 
 		/** @var \OC\App\AppManager $appManager */
 		$appManager = \OC::$server->getAppManager();