fix(shotdown):fix shotdown InternalSignal default value
diff --git a/config/graceful_shutdown_config.go b/config/graceful_shutdown_config.go
index d0779a8..e875c49 100644
--- a/config/graceful_shutdown_config.go
+++ b/config/graceful_shutdown_config.go
@@ -66,7 +66,7 @@
 	// when we try to shutdown the applicationConfig, we will reject the new requests. In most cases, you don't need to configure this.
 	RejectRequestHandler string `yaml:"reject-handler" json:"reject-handler,omitempty" property:"reject_handler"`
 	// internal listen kill signal,the default is true.
-	InternalSignal bool `default:"true" yaml:"internal-signal" json:"internal.signal,omitempty" property:"internal.signal"`
+	InternalSignal *bool `default:"true" yaml:"internal-signal" json:"internal.signal,omitempty" property:"internal.signal"`
 	// offline request window length
 	OfflineRequestWindowTimeout string `yaml:"offline-request-window-timeout" json:"offlineRequestWindowTimeout,omitempty" property:"offlineRequestWindowTimeout"`
 	// true -> new request will be rejected.
@@ -157,7 +157,7 @@
 }
 
 func (scb *ShutdownConfigBuilder) SetInternalSignal(internalSignal bool) *ShutdownConfigBuilder {
-	scb.shutdownConfig.InternalSignal = internalSignal
+	scb.shutdownConfig.InternalSignal = &internalSignal
 	return scb
 }