twbs/bootstrap — pull request #13735 by skhilko (2014-06-04 22:33:59+00:00)
Title: Fix bug where a panel recieve extra top border when placed within a collapsible panel

Fixes https://github.com/twbs/bootstrap/issues/13734

A panel placed inside of a collapsible panel receive extra top border.

This commit reduces the effect of a selector to apply a border only to
the collapsible panel body itself, not to any panel placed within it.