get-developers: fix handling of syntax error
When getdeveloperlib.parse_developers doesn't find anything, the script
tries sys.exit(1) but sys is not imported.
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>