Bug 704896 - pop ups are annoying when opening multiple files...

...from the command line on some platforms/window managers

file_open_from_command_line(): display the progress in the active
display if there is no empty display. This way the progress appears in
the display that was opened from the previous command line argument.

(cherry picked from commit 4fb7fc918ab6f42c31894ffca5f5f80b756d5609)