Refactor navigation menu position in upload wizard

[DavidBlaa]

at the moment the navigation is set to a certain position, so with different resolutions it can happen that you don't see the navigation and you have to scroll.

Edit the wizard so that the navigation is always visible at the bottom, so that nobody has to scroll anymore.

[geofranzi]

let's just remove the fixed height. In most cases nothing to scroll - only in very few cases (e.g. a very long list of columns during update)