Fix camera entity update coordinator subscription in Synology DSM (#72248)

fix camera entity subscription to coordinator

homeassistant/components/synology_dsm/camera.py

@@ -154,6 +154,7 @@ class SynoDSMCamera(SynologyDSMBaseEntity, Camera):
     async def async_added_to_hass(self) -> None:
         """Subscribe to signal."""
         self._listen_source_updates()
+        await super().async_added_to_hass()
 
     def camera_image(
         self, width: int | None = None, height: int | None = None