Update README_CN.md (#1331)

miaogaolin · lunny · commit d0827bfc00ea · 2019-06-19T10:36:23.000+08:00
修改错别字
diff --git a/README_CN.md b/README_CN.md
@@ -362,7 +362,7 @@ if _, err := session.Exec("delete from userinfo where username = ?", user2.Usern
 return session.Commit()
 ```
 
-* 事物的简写方法
+* 事务的简写方法
 
 ```Go
 res, err := engine.Transaction(func(session *xorm.Session) (interface{}, error) {
