Fix regression (broken unit tests)
Fix regression (broken unit tests)

Fixes: 95019a8c ("fix issue #3940 - remove colormap before thresholding")
Signed-off-by: Stefan Weil <8d4c780fcfdc41841e5070f4c43da8958ba6aec0@weilnetz.de>

tesseract-ocr/tesseract,amitdo/tesseract,amitdo/tesseract,tesseract-ocr/tesseract,amitdo/tesseract,amitdo/tesseract,tesseract-ocr/tesseract,tesseract-ocr/tesseract,amitdo/tesseract,tesseract-ocr/tesseract