Avoid $instance, use $host instead, as that works both centrally and on the station

lcu.json

@@ -947,7 +947,7 @@
                 "uid": "prometheus"
               },
               "editorMode": "code",
-              "expr": "avg_over_time(node_hwmon_temp_celsius{instance=\"${station}.astron.nl:9090\", chip=\"platform_coretemp_0\", sensor=\"temp1\"}[10m])",
+              "expr": "avg_over_time(node_hwmon_temp_celsius{host=\"${station}\", chip=\"platform_coretemp_0\", sensor=\"temp1\"}[10m])",
               "legendFormat": "average 10m",
               "range": true,
               "refId": "avg"
@@ -958,7 +958,7 @@
                 "uid": "prometheus"
               },
               "editorMode": "code",
-              "expr": "max(max_over_time(node_hwmon_temp_celsius{instance=\"${station}.astron.nl:9090\",chip=\"platform_coretemp_0\"}[10m]))",
+              "expr": "max(max_over_time(node_hwmon_temp_celsius{host=\"${station}\",chip=\"platform_coretemp_0\"}[10m]))",
               "hide": false,
               "legendFormat": "max 10m",
               "range": true,
@@ -970,7 +970,7 @@
                 "uid": "prometheus"
               },
               "editorMode": "code",
-              "expr": "min_over_time(node_hwmon_temp_celsius{instance=\"${station}.astron.nl:9090\", chip=\"platform_coretemp_0\", sensor=\"temp1\"}[10m])",
+              "expr": "min_over_time(node_hwmon_temp_celsius{host=\"${station}\", chip=\"platform_coretemp_0\", sensor=\"temp1\"}[10m])",
               "hide": false,
               "legendFormat": "min 10m",
               "range": true,
@@ -1061,7 +1061,7 @@
                 "type": "prometheus",
                 "uid": "prometheus"
               },
-              "expr": "node_hwmon_power_average_watt{instance=\"${station}.astron.nl:9090\"}",
+              "expr": "node_hwmon_power_average_watt{host=\"${station}\"}",
               "refId": "A"
             }
           ],