use registry:lookup_type_module inside exchange:type_to_module

Without this change delete/3 callback for custom exchange type wasn't called and warning about invalid exchange type appeared in the logs.
What is interesting that exchange module was logged as an invalid type for previously declared exchange of that module ¯\_(ツ)_/¯.

deps/rabbit/src/rabbit_exchange.erl

@@ -539,7 +539,7 @@ invalid_module(T) ->
 type_to_module(T) ->
     case get({xtype_to_module, T}) of
         undefined ->
-            case rabbit_registry:lookup_module(exchange, T) of
+            case rabbit_registry:lookup_type_module(exchange, T) of
                 {ok, Module}       -> put({xtype_to_module, T}, Module),
                                       Module;
                 {error, not_found} -> invalid_module(T)