management/fetch_data: Add workaround for db API change

Fixes #698.

[patch v2: Added default 'None' to prevent KeyError when using an old
           DB API endpoint]
Signed-off-by: Fabian P. Schmidt <kerel@mailbox.org>

network/base/management/commands/fetch_data.py

@@ -41,6 +41,7 @@ class Command(BaseCommand):
                 satellites_updated += 1
             except Satellite.DoesNotExist:
                 # Add Satellite
+                satellite.pop('telemetries', None)
                 Satellite.objects.create(**satellite)
                 satellites_added += 1