Remove locale overrides from tox

Remove LANG, LANGUAGE, and LC_ALL settings from tox to mirror
https://review.openstack.org/#/c/72233

Change-Id: I410a4dc3de622ddb3886df897de6d9a1311dd2b1

oslo.{{cookiecutter.module_name}}/tox.ini

@@ -12,9 +12,6 @@ envlist = py26,py27,py33,pypy,pep8
 install_command = pip install -U {opts} {packages}
 setenv =
    VIRTUAL_ENV={envdir}
-   LANG=en_US.UTF-8
-   LANGUAGE=en_US:en
-   LC_ALL=C
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 commands = python setup.py testr --slowest --testr-args='{posargs}'