[dataimport] remove deprecated methods from massive store
This code is new in cubicweb, no reason for it to carry deprecated stuff
from the start.
for table, column in [
('transactions', 'tx_time'),
('tx_entity_actions', 'tx_uuid'),
('tx_relation_actions', 'tx_uuid')]:
repo.system_source.create_index(session, table, column)
commit()