Add missing namespace prefix (fix build for merge_unicharsets)
Add missing namespace prefix (fix build for merge_unicharsets)

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

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