Bug 950588 - [Email][V1.3] Cannot get the folder list while you want to move multiple mails

The folder_cards.css was applying to the value_selector styles for folder depth, so the bug only shows up if the folder_picker is shown before going to edit (folder_cards.css is loaded when folder_picker is shown).

Doing a quick git blame does not point to obvious point of breakage in folder_cards.css, value_selector.js or shared/switches.css. These styles have been always unspecific, and suspect this could have been broken for a long time, even as early as April 2, 2013.

Only folder_picker and value_selector use these styles, so this specificity does not affect any other cards.