Removed DiamanteDesk entry as UNUPDATED (#2565)

Signed-off-by: Akashdeep Dhar <akashdeep.dhar@gmail.com>

README.md

@@ -1537,7 +1537,6 @@ _See also [Task management/To-do lists](#task-managementto-do-lists) and [Projec
 
 - [Bugzilla](https://www.bugzilla.org/) - General-purpose bugtracker and testing tool originally developed and used by the Mozilla project. `MPL-2.0` `Perl`
 - [Bumpy Booby](http://bumpy-booby.derivoile.fr/) - Simple, responsive and highly customizable PHP bug tracking system. ([Source Code](https://github.com/piero-la-lune/Bumpy-Booby)) `MIT` `PHP`
-- [DiamanteDesk](http://diamantedesk.com/) - DiamanteDesk is FREE Open Source easy-to-use help-desk solution. ([Demo](http://diamantedesk.com/demo/), [Source Code](https://github.com/eltrino/diamantedesk-application)) `OSL-3.0` `PHP`
 - [django-todo](http://django-todo.org/) - django-todo is a pluggable, multi-user, multi-group, multi-list todo and ticketing system - a reusable app designed to be dropped into any existing Django project. ([Source Code](https://github.com/shacker/django-todo)) `BSD-3-Clause` `Python/Django`
 - [Erxes](https://erxes.io/install/) - Marketing, sales, and customer service platform designed to help businesses attract more engaged customers. ([Demo](https://demo.erxes.io/), [Source Code](https://github.com/erxes/erxes)) `GPL-3.0` `Javascript`
 - [Flyspray](http://www.flyspray.org/) - Uncomplicated, web-based bug tracking system. ([Source Code](https://github.com/Flyspray/flyspray)) `GPL-2.0` `PHP`