[Bugfix] Central band mask off by one pixel for odd shapes
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 * When estimating the sideband position, the mask removing the central band
   was shifted by one pixel for holograms with an odd number of rows or
   columns. Affects
   :func:`~libertem_holo.base.utils.estimate_sideband_position` and
   :meth:`~libertem_holo.base.utils.HoloParams.from_hologram`.