fix(prometheus): Rename instance label to server

Author: tzushimelon

compose/prometheus/config/prometheus.yml

@@ -2,7 +2,7 @@ global:
   scrape_interval: 15s
   evaluation_interval: 15s
   external_labels:
-    instance: "sushii2"
+    server: "sushii2"
 
 remote_write:
   - url: http://pocatov3.tailc8948.ts.net/prometheus/api/v1/write