Fix handling of single pages from multipage TIFF files (issue #2537)
Fix handling of single pages from multipage TIFF files (issue #2537)

That case now uses Leptonica to deliver the desired image instead of
using an inefficient loop in the Tesseract code.

See commit 54fafc4e2e9e2941b643f6cef67a7ec7e0b8bb49 which used similar
code in the past.

Signed-off-by: Stefan Weil <8d4c780fcfdc41841e5070f4c43da8958ba6aec0@weilnetz.de>

tesseract-ocr/tesseract,amitdo/tesseract,tesseract-ocr/tesseract,tesseract-ocr/tesseract,tesseract-ocr/tesseract,stweil/tesseract,UB-Mannheim/tesseract,stweil/tesseract,amitdo/tesseract,amitdo/tesseract,stweil/tesseract,UB-Mannheim/tesseract,UB-Mannheim/tesseract,tesseract-ocr/tesseract,UB-Mannheim/tesseract,amitdo/tesseract,stweil/tesseract,amitdo/tesseract,stweil/tesseract,UB-Mannheim/tesseract