[repo] ensure we don't restart a task while the repo is shutting down (closes #1942736) we need a safety belt in cw itself again looping task which use 'try / except' or doesn't need to access the db (which will trigger ShuttingDown exception)

if schema['TZDatetime'].eid is None:
    add_entity_type('TZDatetime')
if schema['TZTime'].eid is None:
    add_entity_type('TZTime')