fix(fill_db_data.py): retry to truncate
fix(fill_db_data.py): retry to truncate

There is a known scylla issue in truncate, the timeout exception will break the
subtest, and test data won't be prepared for next subtest. Let's retry
truncate in fail to make sure the test data is prepared correctly.

Signed-off-by: Amos Kong <eb01d8f828a6c9a20be4534e72e049aaf41503df@scylladb.com>

scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-longevity-tests,scylladb/scylla-longevity-tests,scylladb/scylla-longevity-tests