Fails to load user language

[lenemter]

What Happened?

Captive Network Assistant doesn't load user language.

(captive-login:2): Gtk-WARNING **: 01:30:18.738: Locale not supported by C library.
	Using the fallback 'C' locale.
Gtk-Message: 01:30:18.755: Failed to load module "canberra-gtk-module"
Gtk-Message: 01:30:18.756: Failed to load module "canberra-gtk-module"

(process:12): Gtk-WARNING **: 01:30:18.799: Locale not supported by C library.
	Using the fallback 'C' locale.
Gtk-Message: 01:30:18.818: Failed to load module "canberra-gtk-module"
Gtk-Message: 01:30:18.819: Failed to load module "canberra-gtk-module"

Tested on Russian and French locales (both are fully translated in master)

Steps to Reproduce

1. Change language to not English one
2. flatpak run io.elementary.capnet-assist

Expected Behavior

The app is translated.

OS Version

7.x (Horus)

Software Version

Latest release (I have run all updates)

Log Output

No response

Hardware Info

No response