Fix availble languages now that mapping no longer happens

config/settings.yml

@@ -158,7 +158,7 @@ available_languages:
   - pt
   - 'pt-BR'
   - it
-  - zh
+  - 'zh-CN'
   - ko
   - ru
 default_language:

db/migrate/20190618115620_fix_available_languages.rb

@@ -0,0 +1,27 @@
+class FixAvailableLanguages < ActiveRecord::Migration[5.2]
+  def up
+    Setting.available_languages = Setting.available_languages.map do |lang|
+      if lang == 'zh'
+        'zh-CN'
+      else
+        lang
+      end
+    end
+
+    User.where(language: 'zh').update_all(language: 'zh-CN')
+  end
+
+  def down
+    Setting.available_languages = Setting.available_languages.map do |lang|
+      if lang == 'zh-CN'
+        'zh'
+      else
+        lang
+      end
+    end
+
+    User.where(language: 'zh-CN').update_all(language: 'zh')
+  end
+
+  private
+end