Merge branch 'dev' of https://github.com/dotnet-architecture/eShopOnContainers into dev

src/Services/Ordering/Ordering.API/Infrastructure/AutofacModules/MediatorModule.cs

@@ -44,9 +44,8 @@ namespace Microsoft.eShopOnContainers.Services.Ordering.API.Infrastructure.Autof
             builder.Register<SingleInstanceFactory>(context =>
             {
                 var componentContext = context.Resolve<IComponentContext>();
-
-                return t => componentContext.Resolve(t);
-            });
+                return t => { object o; return componentContext.TryResolve(t, out o) ? o : null; };
+            });          
 
             builder.Register<MultiInstanceFactory>(context =>
             {