[fix] Handle called_station_id uses "-" instead of ":"

Also made device mac address lookup case insensitive

Author: pandafy

openwisp_radius/integrations/monitoring/tasks.py

@@ -105,7 +105,10 @@ def post_save_radiusaccounting(
         device = (
             Device.objects.select_related('devicelocation')
             .only('id', 'devicelocation__location_id')
-            .get(mac_address=called_station_id, organization_id=organization_id)
+            .get(
+                mac_address__iexact=called_station_id.replace('-', ':'),
+                organization_id=organization_id,
+            )
         )
     except Device.DoesNotExist:
         logger.warning(

openwisp_radius/integrations/monitoring/tests/test_metrics.py

@@ -139,7 +139,7 @@ def test_post_save_radiusaccounting(self, *args):
             {
                 'unique_id': '117',
                 'username': user.username,
-                'called_station_id': device.mac_address,
+                'called_station_id': device.mac_address.replace('-', ':').upper(),
                 'calling_station_id': '00:00:00:00:00:00',
                 'input_octets': '8000000000',
                 'output_octets': '9000000000',