New JCrypTool Update Site for end users

[Dominik Schadow]

Developers, 

This change does not involve immediate action for you. Instead this a step by step instruction for our users.

The JCrypTool update site was moved to http://www.cryptool.org/jct/update. This URL must be updated in JCrypTool manually. 

1. Launch JCrypTool and open the preferences via Window - Preferences (German: Fenster - Einstellungen)
2. Expand the Install/ Update section and select Available Software Sites 
3. There should be one entry with the location http://www.cryptool.org/jcryptool/update
4. Select this entry and click Edit
5. Replace the location link with the new update site URL http://www.cryptool.org/jct/update
6. Click OK to close the dialog and OK to close the preferences

That's it. Now you can use the update manager again.