This is done in a backward-compatible manner: Once an existing profile is saved,
the new format is used.

Opening the new format with an old VLC version will work, too, but you will
lose changes from the new format.

refs #11643

(cherry picked from commit 32693a7ecb132ce10ffe2d64f2d04806be60b861)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>