Revert Fahrenheit to Farenheit

This is a typo in
https://github.com/grafana/grafana/blob/master/public/app/core/utils/kbn.ts#L1051

devenv/dev-dashboards/panel_tests_polystat.json

@@ -884,8 +884,8 @@
               "value": "celsius"
             },
             {
-              "text": "Fahrenheit (°F)",
-              "value": "fahrenheit"
+              "text": "Farenheit (°F)",
+              "value": "farenheit"
             },
             {
               "text": "Kelvin (K)",
@@ -1991,8 +1991,8 @@
               "value": "celsius"
             },
             {
-              "text": "Fahrenheit (°F)",
-              "value": "fahrenheit"
+              "text": "Farenheit (°F)",
+              "value": "farenheit"
             },
             {
               "text": "Kelvin (K)",
@@ -3078,8 +3078,8 @@
               "value": "celsius"
             },
             {
-              "text": "Fahrenheit (°F)",
-              "value": "fahrenheit"
+              "text": "Farenheit (°F)",
+              "value": "farenheit"
             },
             {
               "text": "Kelvin (K)",