remove file if empty

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

plugin.go

@@ -206,6 +206,9 @@ func (p *Plugin) Exec() error {
 	fmt.Println(p.Config.File)
 	fmt.Println(len(p.Config.File))
 	for _, f := range p.Config.File {
+		if f == "" {
+			continue
+		}
 		err := p.SendFile(f)
 		if err != nil {
 			return err