test.py: remove unused black_hole
test.py: remove unused black_hole

Signed-off-by: Amos Kong <eb01d8f828a6c9a20be4534e72e049aaf41503df@scylladb.com>
Message-Id: <2e79a58906e8f3ba512586fe4ea4a662fa1a3d35.1511944232.git.eb01d8f828a6c9a20be4534e72e049aaf41503df@scylladb.com>

avikivity/scylla,avikivity/scylla,scylladb/scylla,duarten/scylla,scylladb/scylla,duarten/scylla,scylladb/scylla,duarten/scylla,avikivity/scylla,scylladb/scylla