feat(files_external): Enable ownerless shares

Signed-off-by: provokateurin <kate@provokateurin.de>

apps/files_external/lib/Config/SystemMountPoint.php

@@ -8,7 +8,8 @@ declare(strict_types=1);
 
 namespace OCA\Files_External\Config;
 
+use OCP\Files\Mount\IShareOwnerlessMount;
 use OCP\Files\Mount\ISystemMountPoint;
 
-class SystemMountPoint extends ExternalMountPoint implements ISystemMountPoint {
+class SystemMountPoint extends ExternalMountPoint implements ISystemMountPoint, IShareOwnerlessMount {
 }