Add default values for Priority and Sound.

src/Ombi.Settings/Settings/Models/Notifications/PushoverSettings.cs

@@ -8,7 +8,7 @@ namespace Ombi.Settings.Settings.Models.Notifications
         public bool Enabled { get; set; }
         public string AccessToken { get; set; }
         public string UserToken { get; set; }
-        public sbyte Priority { get; set; }
-        public string Sound { get; set; }
+        public sbyte Priority { get; set; } = 0;
+        public string Sound { get; set; } = "pushover";
     }
 }