use 0 bytes for hash table value in set

Link: https://github.com/GeneAssembly/biosal/issues/223
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
use 0 bytes for hash table value in set

Link: https://github.com/GeneAssembly/biosal/issues/223
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>