Fix adding bucket forwarder handler in server mode (#14288)

MinIO configuration is loaded after the initialization of the server
handlers, which will miss the initialization of the bucket forwarder
handler.

Though the federation is deprecated, let's fix this for the time being.

cmd/routers.go

@@ -58,6 +58,8 @@ var globalHandlers = []mux.MiddlewareFunc{
 	setRequestValidityHandler,
 	// set x-amz-request-id header.
 	addCustomHeaders,
+	// Add bucket forwarding handler
+	setBucketForwardingHandler,
 	// Add new handlers here.
 }
 
@@ -87,10 +89,6 @@ func configureServerHandler(endpointServerPools EndpointServerPools) (http.Handl
 	// Add API router
 	registerAPIRouter(router)
 
-	// Enable bucket forwarding handler only if bucket federation is enabled.
-	if globalDNSConfig != nil && globalBucketFederation {
-		globalHandlers = append(globalHandlers, setBucketForwardingHandler)
-	}
 	router.Use(globalHandlers...)
 
 	return router, nil