locale.Error: unsupported locale setting exception when glibc locale files are not present

Created by: rathann

Information

Solaar version: 1.0.3
Distribution: Fedora
Kernel version (ex. uname -srmo): Linux 5.7.11-200.fc32.x86_64 x86_64 GNU/Linux
Output of solaar show: N/A

Describe the bug Any solaar invocation is failing with a traceback when locale.setlocale() call fails, e.g. due to missing glibc locale files for the currently set locale.

To Reproduce Steps to reproduce the behavior:

$ sudo dnf remove glibc-langpack-de
$ export LC_ALL=de_CH.UTF-8
$ export LANG=de_CH.UTF-8
$ solaar --help
Traceback (most recent call last):
  File "/usr/bin/solaar", line 59, in <module>
    import solaar.gtk
  File "/usr/lib/python3.8/site-packages/solaar/gtk.py", line 29, in <module>
    import solaar.i18n as _i18n
  File "/usr/lib/python3.8/site-packages/solaar/i18n.py", line 50, in <module>
    locale.setlocale(locale.LC_ALL, '')
  File "/usr/lib64/python3.8/locale.py", line 608, in setlocale
    return _setlocale(category, locale)
locale.Error: unsupported locale setting
$

Additional context Looks like #190 (closed) is still unfixed. Downstream bug report: https://bugzilla.redhat.com/show_bug.cgi?id=1811313 .