Remove dead pkp demo link

README.md

@@ -626,7 +626,7 @@ _Related: [E-commerce](#e-commerce)_
 - [Conference Organizing Distribution (COD)](http://usecod.com/) - Create conference and event websites built on top of Drupal. ([Source Code](https://git.drupalcode.org/project/cod)) `GPL-1.0` `PHP`
 - [frab](https://frab.github.io/frab/) - web-based conference planning and management system. It helps to collect submissions, to manage talks and speakers and to create a schedule. ([Source Code](https://github.com/frab/frab)) `MIT` `Ruby`
 - [indico](https://getindico.io/) - A feature-rich event management system, made @ CERN, the place where the Web was born. ([Demo](https://sandbox.getindico.io/), [Source Code](https://github.com/indico/indico)) `MIT` `Python`
-- [Open Conference Systems (OCS)](https://pkp.sfu.ca/ocs/) - is a free Web publishing tool that will create a complete Web presence for your scholarly conference. ([Demo](https://pkp.sfu.ca/ocs/ocs_demo/), [Source Code](https://github.com/pkp/ocs)) `GPL-1.0` `PHP`
+- [Open Conference Systems (OCS)](https://pkp.sfu.ca/ocs/) - is a free Web publishing tool that will create a complete Web presence for your scholarly conference. ([Source Code](https://github.com/pkp/ocs)) `GPL-1.0` `PHP`
 - [OpenCFP](https://github.com/opencfp/opencfp) - OpenCFP is a PHP-based conference talk submission system. `MIT` `PHP`
 - [osem](https://osem.io/) - Event management tailored to free Software conferences. ([Demo](https://demo.osem.io/), [Source Code](https://github.com/openSUSE/osem)) `MIT` `Ruby`
 - [pretalx](https://pretalx.org) - Web-based event management, including running a Call for Papers, reviewing submissions, and scheduling talks. Exports and imports for various related tools. ([Source Code](https://github.com/pretalx/pretalx)) `Apache-2.0` `Python`