revproxy-03: disable grafana

Grafana has now moved to ffs05, hence disable for ffs03 to avoid the
renew getting stuck.

host_vars/revproxy-03.freifunk-stuttgart.de/revproxy

@@ -41,6 +41,7 @@ vhosts:
   - domain: grafana.freifunk-stuttgart.de
     backend: "http://10.0.3.237/"
     type: proxy
+    enabled: false
   - domain: map02.freifunk-stuttgart.de
     backend: "http://10.0.3.236/"
     type: proxy