[sqlite] Fix integrity error parsing
Up to sqlite 3.7, integrity error message may be in the singular form
if only one column is in the unique index.
Closes #5224632
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()