[pkg] Depend on Pillow instead of PIL
The Pillow library is becoming the de-facto replacement for PIL.
It also is way simpler to install with pip than PIL.
Closes #4411354.
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()