Fix sources of 3 icons and color for XING (#702)
Fix sources of 3 icons and color for XING (#702)

* Update source of Ubuntu, Zendesk, and XING

* Fix XING color

Please see https://github.com/simple-icons/simple-icons/issues/693 for more info

danleech/simpleicons.org,danleech/simpleicons.org,danleech/simple-icons,simple-icons/simple-icons,birjolaxew/simple-icons,birjolaxew/simple-icons,simple-icons/simple-icons