[3.4] Fix CS and the bootstrap dropdown on com_postinstall

This fix CS and the bootstrap dropdown on com_postinstall

#### Bevor Patch

![current_com_postinstall](https://cloud.githubusercontent.com/assets/2596554/4434833/18e651a6-4727-11e4-8b2f-c4a1cd7dc556.JPG)


#### After Patch

![fixed_com_postinstall](https://cloud.githubusercontent.com/assets/2596554/4434837/2280b274-4727-11e4-83a8-9cc0e141bfba.JPG)