Fixed issue #5 (Classification map does not label nodata pixels when calling...

Fixed issue #5 (Classification map does not label nodata pixels when calling classify_image() with unclassified_threshold=None). Added default CMAP nodata value.

Signed-off-by: Daniel Scheffler <danschef@gfz-potsdam.de>
3 jobs for bugfix/fix_nodata_labelling in 3 minutes and 32 seconds