Jar package uninstaller doesn't work on Ubuntu and possible other Linux distros

Steps to reproduce:

• Using Ubuntu/Linux do the following
• download the generic-installer jar
• installation is successful, starting the wiki is successful
• when you want to uninstall, you run the uninstall.jar located in the uninstall directory where the XWiki instalnce is installed

Running from the UI or the console with java -jar uninstall.jar will bring a modal where you must type your username password. After pressing return, the modal disappears but the uninstall does not continue.

This is an old issue, I had it in the past 3 ubuntu versions, so it's not something specific to my Ubuntu version. Maybe it is specific to Ubuntu, but I doubt that.