Bootstrap-theme.css: Navbar .dropdown-menu > .active color overwritten. (width < 769px).

Created by: vsn4ik

Reproduce issue:

1. Open http://jsbin.com/vavoqililuro/1.
2. Make sure that the width of the screen is less than 768px (@grid-float-breakpoint-max).
3. Open collapsed navbar.
4. Open dropdown.
5. Hover on .active link. <-- issue (hover color overwritten).