Fixes broken notification view with newer notifications (openhab#815)

Signed-off-by: Dan Cunningham <dan@digitaldan.com>

openHAB/NotificationsView.swift

@@ -32,7 +32,7 @@ struct NotificationRow: View {
  .frame(width: 40, height: 40)
  .cornerRadius(8)
  VStack(alignment: .leading) {
- Text(notification.message)
+ Text(notification.message ?? "")
  .font(.body)
  if let timeStamp = notification.created {
  Text(dateString(from: timeStamp))

openHAB/OpenHABNotification.swift

@@ -12,13 +12,12 @@
 import Foundation
 
 class OpenHABNotification: NSObject {
- var message = ""
+ var message: String?
  var created: Date?
- var icon = ""
- var severity = ""
+ var icon: String?
+ var severity: String?
  var id = ""
-
- init(message: String = "", created: Date? = nil, icon: String = "", severity: String = "", id: String = "") {
+ init(message: String? = nil, created: Date? = nil, icon: String? = nil, severity: String? = nil, id: String = "") {
  self.message = message
  self.created = created
  self.icon = icon
@@ -51,7 +50,7 @@ class OpenHABNotification: NSObject {
 extension OpenHABNotification {
  public struct CodingData: Decodable {
  let id: String
- let message: String
+ let message: String?
  let v: Int
  let created: Date?