use node API for free space calculation in versions app (same method as trashbin app)

Signed-off-by: Felix Nieuwenhuizen <felix@tdlrali.com>

apps/files_versions/lib/Storage.php

@@ -750,9 +750,11 @@ class Storage {
 			// subtract size of files and current versions size from quota
 			if ($quota >= 0) {
 				if ($softQuota) {
-					$files_view = new View('/' . $uid . '/files');
-					$rootInfo = $files_view->getFileInfo('/', false);
-					$free = $quota - $rootInfo['size']; // remaining free space for user
+					$userFolder = \OC::$server->getUserFolder($uid);
+					if(is_null($userFolder)) {
+						return 0;
+					}
+					$free = $quota - $userFolder->getSize(false); // remaining free space for user
 					if ($free > 0) {
 						$availableSpace = ($free * self::DEFAULTMAXSIZE / 100) - $versionsSize; // how much space can be used for versions
 					} else {