Qt Installer Framework repogen tool for Linux produces garbled filenames

Using the repogen tool for Linux (Ubuntu 18.04) with Qt Installer Framework 3.2 and 3.1 will produced garbled filenames if the files contain non-ascii characters. This problem does not occur with the repogen tool for Windows.

For example, a file titled

简体中文（自动生成）.json

becomes

简体中文（自动生成）.json

This only affects the file names, not the actual content of the files.