Simplifying `modChrome_well`

Simplifying the module chrome `modChrome_well` in Isis template a bit by removing some unneeded code and a `<div>`

- Moved `(int)`to where we get the param instead of after the check
- Removed `empty()`as we set the variable the line above.
- Removed appending `. ''` because appending nothing doesn't do anything :)
- Removed the extra check and `<div>` for the `$moduleClass` and moved ìt into the regular `<div>`

Tracker:
http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=32447