Don't enrich nil updates

pkg/ambient/ambient.go

@@ -85,6 +85,7 @@ func (aw *AmbientWeather) handleProviderRequest(
 
 		w.WriteHeader(http.StatusInternalServerError)
 		w.Write([]byte(err.Error()))
+		return
 	}
 
 	// Calculate any fields that may be missing

pkg/weather/enrich.go

@@ -5,6 +5,10 @@ import "math"
 // Attempts to complete missing fields that may not
 // be set by a specific provider, such as DewPoint and WindChill
 func (u *WeatherUpdate) Enrich() {
+	if u == nil {
+		return
+	}
+
 	if u.WindChillF == 0 {
 		u.WindChillF = CalculateWindChill(u.TempOutdoorF, u.WindSpeedMPH)
 	}