Correct the delete error message

src/device/service/driver_api/Tools.py

@@ -28,7 +28,7 @@ def _set(resource : Tuple[str, Any]):
     return ACTION_MSG_SET.format(*tuple(map(str, resource)))
 
 def _delete(resource : Tuple[str, Any]):
-    return ACTION_MSG_SET.format(*tuple(map(str, resource)))
+    return ACTION_MSG_DELETE.format(*tuple(map(str, resource)))
 
 def _subscribe(subscription : Tuple[str, float, float]):
     return ACTION_MSG_SUBSCRIBE.format(*tuple(map(str, subscription)))