Remove focus selection from input after user's click on it

When user clicks on input (result (check/uncheck) does not matter), it gets selection ![selection](https://f.cloud.github.com/assets/597016/628681/4bbf1cea-d0e3-11e2-8b42-be737cebdf4b.png).

 This looks a bit ugly. Especially when `selectedClass` is `null`. My change fixes that.