correct tab in scala-features.md

Author: benluo

_zh-cn/overviews/scala3-book/scala-features.md

@@ -113,18 +113,6 @@ That is, we don’t write imperative code like this:
 正如函数式编程的说法，在 Scala 中，您编写您想要 _“什么”_，而不是 _“如何”_ 去实现它。
 也就是说，我们不会像这样编写命令式代码：
 
-{% tabs scala-features-1 class=tabs-scala-version %}
-{% tab 'Scala 2' for=scala-features-1 %}
-```scala
-def double(ints: List[Int]): List[Int] = {
-  val buffer = new ListBuffer[Int]()
-  for (i <- ints) {
-      buffer += i * 2
-  }
-  buffer.toList
-}
-
-val newNumbers = double(oldNumbers)
 {% tabs scala-features-1 class=tabs-scala-version %}
 {% tab 'Scala 2' for=scala-features-1 %}
 ```scala