make travis happy again :D

Hehe Travis is a good guy that find a lot of issues :+1: 

```
FILE: /home/travis/build/joomla/joomla-cms/cli/install.php
--------------------------------------------------------------------------------
FOUND 3 ERROR(S) AFFECTING 3 LINE(S)
--------------------------------------------------------------------------------
 231 | ERROR | Please consider the /* */ style for comments that span over
     |       | multiple lines.
 412 | ERROR | Doc comment for "$db" missing
 414 | ERROR | Missing @return tag in function comment
--------------------------------------------------------------------------------
```

I hope he is happy after this :smile: