Forced to select at least one extension in lql init cli

When we use `lql init`, we must choose at least 1 `extension`:
```
Which extensions?
Argument --extensions type [checkbox]
> Your input:
$ 
  ○ bloom
  ○ btree_gin
  ○ btree_gist
  ○ citext
  ○ hstore
  ○ intarray
  ○ pg_trgm
  ○ pgcrypto
> ◉ plpgsql
  ○ plperl

```