owncloud client not supported by owncloud server 10.0.3

[Marco Righi]

After owncloud server upgrade from 9.1.6 to 10.0.3 (the so called owncloud X) the ubuntu 16.04 client can not connect to the server. The error is: "Error downloading https://SERVERNAME/owncloud/remote.php/webdav/ - server replied: Forbidden (Unsupported client version.)". Please upgrade ASAP the owncloud client. It is not possible patch by adding ''deb https://download.opensuse.org/repositories/isv:/ownCloud:/desktop/Ubuntu_16.04/' repository.
Thank you very much.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: owncloud-client 2.1.1+dfsg-1ubuntu1.1
ProcVersionSignature: Ubuntu 4.4.0-96.119-generic 4.4.83
Uname: Linux 4.4.0-96-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
CurrentDesktop: Unity
Date: Wed Sep 20 00:31:42 2017
InstallationDate: Installed on 2016-04-27 (510 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
SourcePackage: owncloud-client
UpgradeStatus: No upgrade log present (probably fresh install)