Revert "locale: Fix incorrect locale name for zh-Hans."

This reverts commit ba8dc62.

As best I can tell, the old configuration was correct for what Django
wanted.  Further testing is required, but this at least brings
.tx/config to match the actual filenames; I think our Chinese
translations have been broken until now.

.tx/config

@@ -1,5 +1,6 @@
 [main]
 host = https://www.transifex.com
+lang_map = zh-Hans: zh_Hans, zh-Hant: zh_Hant
 
 [zulip.djangopo]
 source_file = static/locale/en/LC_MESSAGES/django.po

zerver/tests/test_i18n.py

@@ -40,10 +40,11 @@ def test_accept_language_header(self):
         languages = [('en', u'Register'),
                      ('de', u'Registrieren'),
                      ('sr', u'Региструј се'),
+                     ('zh-hans', u'注册'),
                      ]
 
         for lang, word in languages:
-            response = self.fetch('get', '/login/', 200,
+            response = self.fetch('get', '/integrations/', 200,
                                   HTTP_ACCEPT_LANGUAGE=lang)
             self.assert_in_response(word, response)
 
@@ -52,25 +53,27 @@ def test_cookie(self):
         languages = [('en', u'Register'),
                      ('de', u'Registrieren'),
                      ('sr', u'Региструј се'),
+                     ('zh-hans', u'注册'),
                      ]
 
         for lang, word in languages:
             # Applying str function to LANGUAGE_COOKIE_NAME to convert unicode
             # into an ascii otherwise SimpleCookie will raise an exception
             self.client.cookies = SimpleCookie({str(settings.LANGUAGE_COOKIE_NAME): lang})
 
-            response = self.fetch('get', '/login/', 200)
+            response = self.fetch('get', '/integrations/', 200)
             self.assert_in_response(word, response)
 
     def test_i18n_urls(self):
         # type: () -> None
         languages = [('en', u'Register'),
                      ('de', u'Registrieren'),
                      ('sr', u'Региструј се'),
+                     ('zh-hans', u'注册'),
                      ]
 
         for lang, word in languages:
-            response = self.fetch('get', '/{}/login/'.format(lang), 200)
+            response = self.fetch('get', '/{}/integrations/'.format(lang), 200)
             self.assert_in_response(word, response)