pressure-vessel fails to parse argv that contains non-ASCII chars

For more info https://github.com/ValveSoftware/steam-runtime/issues/349

Apparently the error occurs when we call g_option_context_parse() in wrap.c.

Steam sets the LC_ALL environment variable to C when the main game needs to be executed (to solve this issue https://github.com/ValveSoftware/steam-for-linux/issues/5827) and it seems like this might be the cause of the issue, because if I place export LC_ALL= in _v2-entry-point the crash doesn't happen anymore.

I'm currently investigating what's the best way to fix that.

UPDATE: I narrowed down the cause, that seems to be caused by pressure-vessel-unruntime