fix --no-segmentation bug

[josef821]

if use --no-segmentation tag it not working. i found this bug in kraken.py in line 220:
bounds = Segmentation(type='bbox', text_direction='horizontal-lr', imagename=ctx.meta['base_image'], script_detection=False, lines=[BBoxLine(id=str(uuid.uuid4()), bbox=(0, 0, im.size[1], im.size[0]))])
must change to :
bounds = Segmentation(type='bbox', text_direction='horizontal-lr', imagename=ctx.meta['base_image'], script_detection=False, lines=[BBoxLine(id=str(uuid.uuid4()), bbox=(0, 0, im.size[0], im.size[1]))])

image width and height must change.