[hdf5tomoscan] fix: is_control_frame

tomoscan/esrf/hdf5scan.py

@@ -563,7 +563,7 @@ class HDF5TomoScan(TomoScanBase):
                                                                   ldelta_angle=delta_angle,
                                                                   return_already_reach=return_already_reach)
                     is_control_frame = return_already_reach
-                frame.is_control_frame = is_control_frame
+                frame._is_control_frame = is_control_frame
                 self._frames.append(frame)
                 last_proj_frame = frame
             self._frames = tuple(self._frames)