userpref: rename 'index' parameter to silece compiler warning on the Pi
userpref: rename 'index' parameter to silece compiler warning on the Pi

upbit/libimobiledevice,libimobiledevice-win32/libimobiledevice,upbit/libimobiledevice,Tatsh/libimobiledevice,libimobiledevice/libimobiledevice,libimobiledevice-win32/libimobiledevice,Tatsh/libimobiledevice,Tatsh/libimobiledevice,patweb/libimobiledevice,patweb/libimobiledevice,kalev/libimobiledevice,libimobiledevice-win32/libimobiledevice,kalev/libimobiledevice,Tatsh/libimobiledevice,libimobiledevice/libimobiledevice,patweb/libimobiledevice,upbit/libimobiledevice,libimobiledevice-win32/libimobiledevice,kalev/libimobiledevice