stop css breaking in a popup BS3

Fix when the edit `popup` is inside a `form` with class `form-horizontal` and the CSS breaks in bootstrap 3

**Overriding CSS in Bootstrap 3 theme:**
```
.form-horizontal .form-group {
    margin-left: -15px;
    margin-right: -15px;
}
```
Could you format the comment the way it is in the next declaration block and also mentioning the bug.

Also, there's missing space between selector and starting brace.