make more than one email receipient possible

alert.go

@@ -76,7 +76,10 @@ func sendAlert(deveui string, alertMessage string) {
 	emailalarmactive := getDevEmailAlarmactive(deveui)
 	fmt.Printf("sendAlert: deveui=%s, email=%s, emailalarmactive=%s\n", deveui, email, emailalarmactive)
 	if emailalarmactive == "1" {
-		sendEmail(email, alertMessage)
+		emails := strings.Split(email, ",")
+		for _, em := range emails {
+			sendEmail(em, alertMessage)
+		}
 	}
 }