ncdu: Update to version 1.17

ncdu: Update to version 1.17

- Update from version 1.16 to 1.17
- Update of rootfile not required
- Changelog
	1.17 - 2022-04-28 - ncdu-1.17.tar.gz
	    Add ‘dark-bg’ color scheme and use that by default
	    Use natural sort order when sorting by file name
	    Improve compatibility with C89 environments
	    Fix wrong assumption about errno not being set by realloc()

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Reviewed-by: Peter Müller <peter.mueller@ipfire.org>