[server] improve TZDatetime support
by depending on logilab-database 1.15.0 including
https://www.logilab.org/ticket/1485893, we can now keep the tzinfo
attribute on datetime objects for TZDatetime attributes, so one knows
that this is a tz-aware datetime.
To easily make it work with backends that have no tz support, we keep
converting tz-aware datetime objects into utc naive datetime objects
before sending them to the database.
# re-read ComputedRelation permissions from schema.py now that we're
# able to serialize them
for computedrtype in schema.iter_computed_relations():
sync_schema_props_perms(computedrtype.type)