osx_notification: Remove "item-change" callback
osx_notification: Remove "item-change" callback

Notify as soon as the current input item is changed,
as it is not a good idea to rely on an item-change
eventually happening later.
This will result in some items that are added and played
immediately lacking metadata in their notifications but
this seems like an acceptable edge case.

xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc