Removal of button in UI

[Bastien Nocera <hadess hadess net>]

Heya,

Just realised today that a button in the Language tab of the Region
panel in System Settings is completely useless, and was never hooked up
to anything:
https://bugzilla.gnome.org/show_bug.cgi?id=684864

GNOME 3.4 and 3.6 are affected. Do you think that committing this to
GNOME 3.6 for the 3.6.1 release would be a problem at this point? If the
button has actually been documented, I guess nobody actually tested it
until now...

Cheers