Also add station name to total scraping duration

docker-compose/tango-prometheus-exporter/code/tango-prometheus-client.py

@@ -208,7 +208,7 @@ class CustomCollector(object):
         scrape_end = time.time()
         logger.info(f"Done scraping. Took {scrape_end - scrape_begin} seconds.")
 
-        scraping_metrics.add_metric(["total"], scrape_end - scrape_begin)
+        scraping_metrics.add_metric([self.station, "total"], scrape_end - scrape_begin)
         
         yield attribute_metrics
         yield scraping_metrics