Setting LC_MESSAGES: prevent unparseable messages

This locale variable defines how tools should display their messages.
This is for example gonna change the yum message from "Nothing to do" to
"Rien a faire" in my case (french).

As the yum module parses that string in err, if the message is not
enforced in english this is gonna fail.

So this commits just enriches a bit more the code that's already written
for that enforcement.

This commit fixes issue #9635.

lib/ansible/runner/shell_plugins/sh.py

@@ -29,6 +29,7 @@ class ShellModule(object):
         env = dict(
             LANG     = C.DEFAULT_MODULE_LANG,
             LC_CTYPE = C.DEFAULT_MODULE_LANG,
+            LC_MESSAGES = C.DEFAULT_MODULE_LANG,
         )
         env.update(kwargs)
         return ' '.join(['%s=%s' % (k, pipes.quote(unicode(v))) for k,v in env.items()])