fix crash of sqlite in release mode

Billing.Shared/Helper.cs

@@ -39,6 +39,7 @@ namespace Billing
 
         public static void Error(string category, Exception ex)
         {
+            MainThread.BeginInvokeOnMainThread(async () => await Shell.Current.DisplayAlert(category, ex.ToString(), "Ok"));
         }
 
         public static void Error(string category, string message)
@@ -139,15 +140,10 @@ namespace Billing
         public delegate void PropertyValueChanged<TResult, TOwner>(TOwner obj, TResult old, TResult @new);
     }
 
-    internal class AsyncLazy<T>
+    public class AsyncLazy<T>
     {
         private readonly Lazy<Task<T>> instance;
 
-        public AsyncLazy(Func<T> factory)
-        {
-            instance = new Lazy<Task<T>>(() => Task.Run(factory));
-        }
-
         public AsyncLazy(Func<Task<T>> factory)
         {
             instance = new Lazy<Task<T>>(() => Task.Run(factory));