[dataimport] remove replace_sep parameter from massive store
It is unused since changeset efbbf1e93a04 "[dataimport] Properly escape
strings sent to COPY FROM"
change_attribute_type('CWCache', 'timestamp', 'TZDatetime')
change_attribute_type('CWUser', 'last_login_time', 'TZDatetime')
change_attribute_type('CWSource', 'latest_retrieval', 'TZDatetime')
drop_attribute('CWSource', 'synchronizing')
add_attribute('CWSource', 'in_synchronization')