package/opencv3: add .hash file
Similar to jquery-keyboard, it seems the opencv3 tarball on the
autobuilder is corrupt. Fix it by adding a .hash file so it falls back to
our s.b.o mirror.
Signed-off-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Romain Naour