Fixes #7157 - Combo box style in reports

This is how it looks like now:
http://imgur.com/k8MgyWp.png
I suggest to get kyle baker's opinion of these UI issues. I'm not sure we need to create an inline form. I suggest to change this PR just to use bootstrap 3 classes and create a separate issue if you want to change the label text from "Show log messages:" to "Show" and remove the line break.