The old qt_zh_CN.qm file in the release is a copy of the Qt 4.8 version of the translated strings and not the Qt 5 one

The old qt_zh_CN.qm file in the release is a copy of the Qt 4.8 version of the translated strings and not the Qt 5 one, this could be because there is no translation available really for zh_CN in Qt 5 as most of it is untranslated.