!24 [Fix] Nil pointer dereference in DevContainer Docker Agent

* [Lint] Replace 4 spaces with 1 Tab (in accordance with `/.editorconfig`)
* [Fix] Fix nullptr dereference

services/devstar_devcontainer/docker_agent/AssignDevcontainerGettingDockerOperator.go

@@ -12,10 +12,13 @@ import (
 func AssignDevcontainerGettingDockerOperator(ctx *context.Context, opts *devcontainer_service_options.OpenDevcontainerAppDispatcherOptions) (uint16, error) {
 	// 1. 创建docker client
 	cli, err := CreateDockerClient(ctx)
-	defer cli.Close()
 	if err != nil {
 		return 0, err
 	}
+	if cli != nil {
+		defer cli.Close()
+	}
+
 	// 获取容器详细信息
 	containerJSON, err := cli.ContainerInspect(context.Background(), opts.Name)
 	if err != nil {
@@ -39,6 +42,6 @@ func AssignDevcontainerGettingDockerOperator(ctx *context.Context, opts *devcont
 	}
 	return 0, devcontainer_service_errors.ErrOperateDevcontainer{
 		Action:  "Open DevContainer in docker",
-		Message: err.Error(),
+		Message: "cannot find SSH containerPort 22 for DevContainer " + opts.Name,
 	}
 }