Fix #883 (#888)

Author: Pliner

Source/EasyNetQ/DI/DefaultServicesRegistration.cs

@@ -20,7 +20,7 @@ public static void RegisterDefaultServices(this IServiceRegister container)
             // default service registration
             container
                 .Register<IConnectionStringParser, ConnectionStringParser>()
-                .Register<ISerializer, JsonSerializer>()
+                .Register<ISerializer>(_ => new JsonSerializer())
                 .Register<IConventions, Conventions>()
                 .Register<IEventBus, EventBus>()
                 .Register<ITypeNameSerializer, DefaultTypeNameSerializer>()