[ISSUE 293] Mini theme was not showing the channels tree

Fixed [one bug](https://github.com/prawnsalad/KiwiIRC/issues/293) from the "Mini" theme where it would not show the channel list as a vertical list. 

The final result:
![Final result](http://img856.imageshack.us/img856/545/screenshot20130611at218.png)

This bug is present in the current stable version (and in the oficial server at https://kiwiirc.com/client ...)