Fixes uninitialized constant error under Rails 3.2

```
NameError: uninitialized constant Bootstrap::Sass::Script
```

I was getting the error above when using `anjlab-bootstrap-rails` in a Rails 3.2.13 app and JRuby 1.7.1. I didn't had any problem though under Rails 4 and JRuby 1.7.4, but this small change should fix the module resolution problem.