Fixes a trivial bug in dumped parse/query/plan trees

Hi Hackers,

This patch fixes a trivial bug where an extra whitespace was added
when dumping an array, for example:

```
  :sort.numCols 2
  :sort.sortColIdx ( 1 4)
  :sort.sortOperators ( 97 1754)
  :sort.collations ( 0 0)
  :sort.nullsFirst ( false false)
```

The unnecessary whitespace is now removed.

Regard regards,