[#] Fix spinner not appearing while installing language

## Description
This old change make this javascript to stop working: https://github.com/joomla/joomla-cms/commit/08658c34cbc45db8e578277a468517a756e2846d because the ID selector (#) was removed.

## Testing instructions
- Do all Joomla Install steps until the last sceen, and in the same installer go to "install languages"

![screen shot 2014-01-09 at 11 11 28](https://f.cloud.github.com/assets/1375475/1876681/5aa5a536-7916-11e3-873e-1ee2685168e5.png)

- Choose several languages from the list and click next

![screen shot 2014-01-09 at 11 13 29](https://f.cloud.github.com/assets/1375475/1876691/8622414c-7916-11e3-94b2-f05cff3efcc6.png)

- When you apply the patch you should be able to see a spinner with a text saying that the installation may take several seconds (without the patch this was not working):

![screen shot 2014-01-09 at 11 13 40](https://f.cloud.github.com/assets/1375475/1876706/b32c065a-7916-11e3-8273-0c568f70e284.png)