[ubuntu] How to set browser for scanning backups?

Dear everyone,
up to know I used urbackupclientgui on ubuntu 16.04 (as root user) to browse my backups. Clicking on “access/restore backups” caused a konqueror browser to be launched.
Now I am under ubuntu 18.04 and the same action causes google chrome to be launched as root with the following error: no browser can be launched as root without the “–no-sandbox” option. I tried to uninstall chrome but has a similar error with firefox.
I would like to know how I can set the default browser opened by urbackupclientgui please.
The client version is v2.4.9.0

Thank you!

It uses this wxWidgets function: https://docs.wxwidgets.org/stable/group__group__funcmacro__misc.html#ga3ff36fe489da2a779248b56f283615ca

So this is more of a wxWidgets issue (wxGtk) https://forums.wxwidgets.org/

Thank you; I will try to find how to set the default browser in wxWidgets.
I temporarily solved the issue by changing
wxLaunchDefaultBrowser("file:///" + fileurl);
wxExecute("/usr/bin/google-chrome --no-sandbox file:///" + fileurl);
in client/TrayIcon.cpp