Digoo HAMB: Tamper needs to be optional.

As this was active in the original report, it was present, but in later attempt
the dp was missing.

Issue #2399

custom_components/tuya_local/devices/digoo_hamb_alarm.yaml

@@ -1,3 +1,4 @@
+
 name: Alarm system
 products:
   - id: a4xyigjpkcmfafvh
@@ -199,6 +200,7 @@ secondary_entities:
     dps:
       - id: 104
         type: string
+        optional: true
         name: sensor
         mapping:
           - dps_val: TAMPER