Remove unneeded messages.po file

conf/locale/config.yaml

@@ -152,7 +152,6 @@ generate_merge:
         - django-studio.po
         - mako.po
         - mako-studio.po
-        - messages.po
         - wiki.po
     djangojs.po:
         - djangojs-partial.po

conf/locale/en/LC_MESSAGES/messages.po

-# edX translation file
-# Copyright (C) 2013 edX
-# This file is distributed under the GNU AFFERO GENERAL PUBLIC LICENSE.
-# 
-msgid ""
-msgstr ""
-"Project-Id-Version: EdX Studio\n"
-"Report-Msgid-Bugs-To: translation_team@edx.org\n"
-"POT-Creation-Date: 2013-05-02 13:13-0400\n"
-"PO-Revision-Date: 2013-05-02 13:27-0400\n"
-"Last-Translator: \n"
-"Language-Team: translation team <translation_team@edx.org>\n"
-"MIME-Version: 1.0\n"
-"Content-Type: text/plain; charset=UTF-8\n"
-"Content-Transfer-Encoding: 8bit\n"
-"Language: en\n"
-
-# empty
-msgid "This is a key string."
-msgstr ""