Make isAdmin async

src/Managing.Api/Controllers/TradingController.cs

@@ -220,7 +220,7 @@ public class TradingController : BaseController
     private async Task<bool> CanUserInitializeAddress(string userName, string publicAddress)
     {
         // Admin users can initialize any address
-        if (_adminService.IsUserAdmin(userName))
+        if (await _adminService.IsUserAdminAsync(userName))
         {
             _logger.LogInformation("Admin user {UserName} initializing address {Address}", userName, publicAddress);
             return true;