[gnome-calculator] Remove British English translation disguised as en_US

[Piotr Drąg <piotrdrag src gnome org>]

commit 9c1d34d64756c5c7a70baa6830bb91e96320694d
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Tue Sep 23 01:49:24 2014 +0200

    Remove British English translation disguised as en_US
    
    We have the real British translation in po/en_GB.po.
    And it's not like we need American English translation anyway.

 po/en_US.po | 1671 -----------------------------------------------------------
 1 files changed, 0 insertions(+), 1671 deletions(-)