[BUG] HDF5Writer cannot be deconfigure when in error state
The bug occurred while testing the provision description 'SBAND_DUALPOL'.
Reproduce:
- ?provision SBAND_DUALPOL
- ?configure -> Note: GatesSpectrometer needs to fail here (force failing the predecessor pipeline)
- ?deconfigure
Reply from KATCP server:
!deconfigure fail 'deconfigure' request failed in hdf5_writer with error: b"'NoneType' object has no attribute 'stop'"