Files with unicode names sent by http file upload fail to open

Versions

OS: Debian 10 with KDE
Gajim version: 1.1.92+gajim@58bb2d25
GTK version: 3.24.5
Python-nbxmpp version: 0.9.93
PyGObject Version: 3.34.

Steps to reproduce the problem

Receive a file sent by http send with the name 'XT60-M镀金规格书_A.01.1'
Click the received file link in Gajim to open it
Press open in the confirmation message box that appears asking whether to open the file

Expected behavior

The pdf file should open with Okular or another PDF viewer, preferably with the default PDF viewer from KDE

Actual behavior

The file fails to open with the following error:

12/24/19 13:59:14 (E) gajim.c.helpers  g-io-error-quark: Error when getting information for file “/home/bfs/.local/share/gajim/downloads/XT60-M镀金规格书_A.01.1__055e39203f.pdf”: No such file or directory (1)
Traceback (most recent call last):
  File "/home/bfs/apps/gajim/gajim/common/helpers.py", line 1475, in func_wrapper
    result = func(self, *args, **kwargs)
  File "/home/bfs/apps/gajim/gajim/common/helpers.py", line 1589, in open_file
    Gio.AppInfo.launch_default_for_uri(path)

Note: the file gets downloaded into ~/.local/share/gajim/downloads/XT60-F%E9%95%80%E9%87%91%E8%A7%84%E6%A0%BC%E4%B9%A6_A.01.1__5e3b6a7c2c.pdf

I guess that the problem appears because of the unicode characters in the filename not being handled properly.

This problem didn't exist before implementing the new file opening handlers based on mimeapps.list

The content of the mimeapps.list file:

[Default Applications]
x-scheme-handler/mailto=shift-application.desktop
image/bmp=org.kde.gwenview.desktop
image/gif=org.kde.gwenview.desktop
image/jpg=org.kde.gwenview.desktop
image/tiff=org.kde.gwenview.desktop
image/x-bmp=org.kde.gwenview.desktop
image/png=org.kde.gwenview.desktop
application/pdf=org.kde.okular.desktop