Merge pull request astaxie#1060 from wybcp/patch-1

Update 12.1.md

Author: astaxie

zh/12.1.md

@@ -22,9 +22,9 @@ import (
 )
 
 func main() {
-log.WithFields(log.Fields{
-	"animal": "walrus",
-}).Info("A walrus appears")
+	log.WithFields(log.Fields{
+		"animal": "walrus",
+	}).Info("A walrus appears")
 }
 ```
 ### 基于logrus的自定义日志处理