REPL doesn't indent caret correctly in error messages

The REPL doesn't indent the caret correctly:

```
scala> val a = List(1)
a: scala.collection.immutable.List[Int] = List(1)
scala> a+1
  ^
a+1
<console>:6: error: type mismatch:
 found   : Int(1)
 required: String
```

It should point to the `1`
