vm/windows: Update sha256 of Cygwin's setup.ini.

This is kinda stupid to do every little time the file is automatically
regenerated upstream. But let's see how often that happens and whether
it will become a major annoyance or not, and if yes, we might be forced
to include it in our source tree.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>