fix bug with filter potentially being used multiple times

brian_dashboard_manager/grafana/provision.py

@@ -303,10 +303,10 @@ def _provision_interfaces(config, org_config, ds_name, token):
 
     relevant_interfaces = list(filter(excluded, interfaces))
     for interface in relevant_interfaces:
-        interface['dashboards_info'] = filter(
+        interface['dashboards_info'] = list(filter(
             lambda x: x['name'] != '',
             interface['dashboards_info']
-        )
+        ))
 
     # loop over interfaces and add them to the dashboard_name
     # -> folder mapping structure `dashboards` above, for convenience.