djeuscan/scan_portage: fix purge-packages and purge-versions

purge-packages: purge package that are not found in the tree
purge-versions: purge versions that are not found in the tree

Also, only purge versions of packages specified on the command line
when called without --all.

Signed-off-by: Corentin Chary <corentin.chary@gmail.com>

euscanwww/djeuscan/management/commands/scan_portage.py

@@ -49,7 +49,6 @@ class Command(BaseCommand):
 
         if options['all']:
             packages = None
-
         elif len(args):
             packages = [pkg for pkg in args]
         else: