twbs/bootstrap — pull request #15307 by vsn4ik (2014-12-05 18:01:05+00:00)
Title: Fix part of #15148.

Reproduce issue:
1. Open: http://jsbin.com/zarecedade/2/edit?html,css,output.
2. Make sure that the screen is more "Extra small devices Phones" (>=768px).
3. Open Dropdown 2 (margin-bottom: 2px).