fix, set default application name if it's empty (#2518)

diff --git a/common/constant/env.go b/common/constant/env.go
index b5e4aca..55283ef 100644
--- a/common/constant/env.go
+++ b/common/constant/env.go
@@ -19,6 +19,7 @@
 
 // nolint
 const (
+	DefaultDubboApp      = "dubbo.io"
 	ConfigFileEnvKey     = "DUBBO_GO_CONFIG_PATH" // key of environment variable dubbogo configure file path
 	AppLogConfFile       = "AppLogConfFile"
 	PodNameEnvKey        = "POD_NAME"
diff --git a/config/application_config.go b/config/application_config.go
index 5bbdbdd..6bdf837 100644
--- a/config/application_config.go
+++ b/config/application_config.go
@@ -19,7 +19,6 @@
 
 import (
 	"github.com/creasty/defaults"
-
 	"github.com/pkg/errors"
 )
 
@@ -54,6 +53,9 @@
 	if err := ac.check(); err != nil {
 		return err
 	}
+	if ac.Name == "" {
+		ac.Name = constant.DefaultDubboApp
+	}
 	return nil
 }