Merge pull request #2015 from rohitwaghchaure/chinese_language_patch_fix

[Fix] Chinese language rename patch

frappe/patches/v7_1/rename_chinese_language_codes.py

@@ -3,6 +3,8 @@ import frappe
 def execute():
 	frappe.rename_doc('Language', 'zh-cn', 'zh', force=True,
 		merge=True if frappe.db.exists('Language', 'zh') else False)
-	frappe.rename_doc('Language', 'zh-tw', 'zh-TW', force=True)
+	if frappe.db.get_value('Language', 'zh-tw') == 'zh-tw':
+		frappe.rename_doc('Language', 'zh-tw', 'zh-TW', force=True)
+
 	frappe.db.set_value('Language', 'zh', 'language_code', 'zh')
 	frappe.db.set_value('Language', 'zh-TW', 'language_code', 'zh-TW')