Fix: Remove broken link

Remove the SysID link that didn't work anymore. Closes #97

documentation/index.Rmd

@@ -24,7 +24,7 @@ This documentation is intended to describe the [SysNDD](https://sysndd.dbmr.unib
 
 ## History of SysID and SysNDD {-}
 
-SysNDD is based on its predecessor [SysID](https://www.sysid.dbmr.unibe.ch/), conceived by Annette Schenck and Christiane Zweier in 2009 and published in 2016 [@kochinke_systematic_2016]. Christiane Zweier has been involved in establishing and updating SysID from its start. She has since performed and coordinated curation and regular updates.
+SysNDD is based on its predecessor SysID, conceived by Annette Schenck and Christiane Zweier in 2009 and published in 2016 [@kochinke_systematic_2016]. Christiane Zweier has been involved in establishing and updating SysID from its start. She has since performed and coordinated curation and regular updates.
 
 The PHP based SysID web tool (Yii 2 framework) was however not further developed and maintained besides necessary bugfixes. After the maintenance agreement for the original server at the CMBI at Radboud University in Nijmegen ran out, the installation was moved to a virtual server at the Department for BioMedical Research (DBMR) at the University Bern. The former link from the initial publication is redirected so it still works. The legacy code base was updated to allow installation and security fixes and to be uploaded to a [GitHub repository (SysID)](https://github.com/berntpopp/SysID). After the first SysNDD native updates to the curated entities, we display a warning popup on the SysID page to show that the content is not curated any more.