Update temperature rename in sample panel

Update grafana today and saw a "Value #A" column where temperature
should be in the temperature table. This should be a backwards
compatible change.

assets/dashboards/ohm-prometheus.json

@@ -721,7 +721,7 @@
             },
             "indexByName": {},
             "renameByName": {
-              "Value": "Temperature",
+              "Value #A": "Temperature",
               "hardware": "Hardware",
               "sensor": "Sensor"
             }