App: Improve auto update behaviour

Elwig/App.xaml.cs

@@ -104,6 +104,9 @@ namespace Elwig {
             try {
                 await AppDbUpdater.CheckDb();
             } catch (Exception e) {
+                if (Config.UpdateUrl != null && Utils.HasInternetConnectivity()) {
+                    await CheckForUpdates();
+                }
                 MessageBox.Show($"Invalid Database:\n\n{e.Message}", "Invalid Database", MessageBoxButton.OK, MessageBoxImage.Error);
                 Shutdown();
                 return;

Elwig/Helpers/Utils.cs

@@ -407,9 +407,11 @@ namespace Elwig.Helpers {
                 using var client = new HttpClient() {
                     Timeout = TimeSpan.FromSeconds(5),
                 };
+                client.DefaultRequestHeaders.Accept.Clear();
+                client.DefaultRequestHeaders.Accept.Add(new("application/json"));
                 var res = JsonNode.Parse(await client.GetStringAsync(url));
                 var data = res!["data"]![0]!;
-                return ((string)data["version"]!, (string)data["url"]!, (int)data["size"]!);
+                return ((string)data["version"]!, (string)data["url"]!, (long)data["size"]!);
             } catch {
                 return null;
             }