sane-backends: bump to version 1.0.25

- Bump version to 1.0.25
- Update hash file. The hash value provided by the alioth.debian.org URL
  is wrong, so use the one provided by www.sane-project.org. I have
  reported this upstream.
- Remove unnecessary patches:
  0002-remove-unsafe-headers-path.patch
  0003-remove-cups-and-systemd-support.patch

Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>