Godot don't work with non-English layout of keyboard on Linux

[FallenNephalem]

Godot version: 3.2.3 stable release

OS/device including version: Linux Mint 18.3

**Issue description: I have 2 layout on my laptop (English and Russian for me) and when i change it to non-English layout happends:

1. Hotkey is not working
2. When i run the project and trying to catch action by if Input.is_action_pressed("ui_right") it doesn't work
3. When i try see scancode of character, i see 0 for all keys, if it not a special key (like "shift", "control", "tab" and etc.)**

Steps to reproduce: For reproduce this bug you can try to catch any action or InputEventKey and see it (of course, you need to do it on linux)

**Minimal reproduction project:game.zip

[bruvzg]

In the master, it should be fixed by #18020 (by falling back to the physical code if remapping failed). I had encountered a similar issue while testing it on different Linux VMs (not sure what exactly is causing it, on most distros non-Latin scan codes work fine).

[madmiraal]

Fixed on master with #18020 and on 3.x with #46764.