"global" auto-CoR fails when scipy is not installed

For some reason the latest "global" auto-CoR fails when scipy is not installed.

Without scipy:

(2020.4.0) (base) lbs191:/nobackup/lbs191tmp1/nabu % nabu nabu.conf  --slice middle
Matplotlib not available. Plotting disabled
Loaded flats/darks from /lbsram/pierre/nabu_processes.h5
Traceback (most recent call last):
  File "/nobackup/lbs191tmp1/nabu/2020.4.0/bin/nabu", line 8, in <module>
    sys.exit(main())
  File "/nobackup/lbs191tmp1/nabu/2020.4.0/lib/python3.8/site-packages/nabu/resources/cli/reconstruct.py", line 111, in main
    proc = ProcessConfig(args["input_file"])
  File "/nobackup/lbs191tmp1/nabu/2020.4.0/lib/python3.8/site-packages/nabu/resources/processconfig.py", line 74, in __init__
    self._get_cor()
  File "/nobackup/lbs191tmp1/nabu/2020.4.0/lib/python3.8/site-packages/nabu/resources/processconfig.py", line 87, in _get_cor
    cor = self.corfinder.find_cor(search_method=cor)
  File "/nobackup/lbs191tmp1/nabu/2020.4.0/lib/python3.8/site-packages/nabu/resources/cor.py", line 120, in find_cor
    shift = self.cor.find_shift(
  File "/nobackup/lbs191tmp1/nabu/2020.4.0/lib/python3.8/site-packages/nabu/preproc/alignment.py", line 787, in find_shift
    cor_position = super(self.__class__, self).find_shift(
  File "/nobackup/lbs191tmp1/nabu/2020.4.0/lib/python3.8/site-packages/nabu/preproc/alignment.py", line 602, in find_shift
    fitted_shifts_vh = self.refine_max_position_2d(f_vals, fv, fh)
  File "/nobackup/lbs191tmp1/nabu/2020.4.0/lib/python3.8/site-packages/nabu/preproc/alignment.py", line 176, in refine_max_position_2d
    raise ValueError(
ValueError: Fitted (y: -669.1166490950043, x: -98.29805309776903) positions are outide the input margins y: [-626.0, -624.0], and x: [-99.0, -97.0]

When scipy is installed, the auto-CoR goes smoothly:

(2020.4.0) (base) lbs191:/nobackup/lbs191tmp1/nabu % nabu nabu.conf  --slice middle
Matplotlib not available. Plotting disabled
Loaded flats/darks from /lbsram/pierre/nabu_processes.h5
Overwriting config file start_z to 1080 and end_z to 1080
Going to reconstruct slices (1080, 1080)

Processing sub-volume (1080, 1081)
Estimated center of rotation: 454.50
File already exists: /lbsram/pierre/wobble_test_1_0001_rec/wobble_test_1_0001_rec_1080.hdf5. It will be overwritten as requested in configuration
Reading data
Applying flat-field
Taking logarithm
Building sinograms
Reconstruction
Saving data
Wrote /lbsram/pierre/wobble_test_1_0001_rec/wobble_test_1_0001_rec_1080.hdf5
File /lbsram/pierre/wobble_test_1_0001_rec.hdf5 already exists. Overwriting as requested in configuration file
Merging reconstructions to /lbsram/pierre/wobble_test_1_0001_rec.hdf5

There must be a difference in the implementation of some filter.