fix pos settings savings for notifications

closes #751

BTCPayServer/Controllers/AppsController.PointOfSale.cs

@@ -178,7 +178,10 @@ namespace BTCPayServer.Controllers
                 CustomButtonText = vm.CustomButtonText,
                 CustomTipText = vm.CustomTipText,
                 CustomTipPercentages = ListSplit(vm.CustomTipPercentages),
-                CustomCSSLink = vm.CustomCSSLink
+                CustomCSSLink = vm.CustomCSSLink,
+                NotificationUrl = vm.NotificationUrl,
+                NotificationEmail = vm.NotificationEmail
+                
             });
             await UpdateAppSettings(app);
             StatusMessage = "App updated";

BTCPayServer/Controllers/AppsPublicController.cs

@@ -269,6 +269,7 @@ namespace BTCPayServer.Controllers
                     NotificationEmail = settings.NotificationEmail,
                     RedirectURL = redirectUrl ?? Request.GetDisplayUrl(),
                     FullNotifications = true,
+                    ExtendedNotifications = true,
                     PosData = string.IsNullOrEmpty(posData) ? null : posData
                 }, store, HttpContext.Request.GetAbsoluteRoot(),
                 new List<string>() {AppService.GetAppInternalTag(appId)},