speedo: Allow use of SHA-256 checksums
* build-aux/getswdb.sh: Add option --find-sha256sum. * build-aux/speedo.mk (libgpg_error_sha2): New var. Also for all other packages. (SHA2SUM): New. (SETVARS, SETVARS_W64): Prefer sha256sum over sha1sum. (installer-from-source): Create swdb fragment.
- Signed-off-by: Werner Koch <wk@gnupg.org>