[PATCH] fix checking whether header is member of message-hidden-headers

[David Bremner]

On Mon, 22 Aug 2011 14:59:02 +0300, Tomi Ollila <tomi.ollila at iki.fi> wrote:
> 
> Emacs lisp function 'member' takes element and list as an
> argument. I.e. the second argument is list, not symbol
> referencing the list.
> On emacs 23.x the member call always returned nil (thus buggy),
> on emacs 22.x the call failed, making it unusable.

Pushed.