Fix for starting 2.1 -> 2.2 -> 2.1 -> 2.2
Fix for starting 2.1 -> 2.2 -> 2.1 -> 2.2

When you start an older version of the application, it writes old config files. When you start the newest version, it moves those config files to the /old/n directory. When you start the old version again, it creates new config files, and when you then start the newest version, it couldn't move those old-version config files to /old/n because there were already files in there. Now it overwrites those old old-version files.

Contributes to issue CURA-844.

onitake/Uranium,onitake/Uranium