[migration] don't crash when deleting a non-existing rtype
When asked to delete a relation type, instead of checking if it was
computed or not, just delete both the CWRType and CWComputedRType.
sync_schema_props_perms('State')
sync_schema_props_perms('state_of')
sync_schema_props_perms('BaseTransition')
sync_schema_props_perms('Transition')
sync_schema_props_perms('WorkflowTransition')
sync_schema_props_perms('transition_of')