Beca BAC002: make schedule optional

User unable to re-add these devices.  Maybe a firmware update on the devices,
or just the fact they are off.
Issue #950

custom_components/tuya_local/devices/beca_bac002_thermostat_c.yaml

@@ -75,6 +75,7 @@ secondary_entities:
       - id: 4
         type: string
         name: option
+        optional: true
         mapping:
           - dps_val: "0"
             value: program