[dbapi] fix connect backwards compat harder Passing None as group and host should result in "pyro:///cubicweb.appid", not "pyro://None/None.appid". Followup for 2091d275fe5c. Closes #2882666.

sync_schema_props_perms('cw_source', syncprops=False)
if schema['BigInt'].eid is None:
    add_entity_type('BigInt')