build: upgrade cnf to latest bndtools status

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>
findbugs: update includes file

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>
findbugs: fix a warning and ignore false positives

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>