WebHost with Environment fix

program.cs

            var builder = Host.CreateDefaultBuilder(args)
                   .ConfigureWebHostDefaults(
                       webBuilder =>
                       {
                           webBuilder
                               .UseStartup<Startup>()
                               .ConfigureAppConfiguration(app =>
                               {
                                   var finding = app.Sources.Where(s => s is EnvironmentVariablesConfigurationSource).SingleOrDefault() as EnvironmentVariablesConfigurationSource;
                                   if (finding != null)
                                   {
                                       int oldIndex = app.Sources.IndexOf(finding);
                                       var newSource = new ExtendedEnvironmentVariablesConfigurationSource();
                                       newSource.NormalizeKeyCallback = (key) =>
                                       {
                                           int logLevelIndex = key.IndexOf("LogLevel:", StringComparison.InvariantCultureIgnoreCase);
                                           if (logLevelIndex > -1)
                                           {
                                               return key.Replace("_", ".");
                                           }
                                           return key;
                                       };
                                       app.Sources[oldIndex] = newSource;
                                   }
                               });
                       });