Bug with shader conf like psx.shaders=/ in last release

[voljega]

In latest version not the beta one, there is a bug when defining no shaders for a specific emulator like :

psx.shaders=/
atarist.shaders=/

in my recalbox.conf I have

## Shader set 
## Automatically select shaders for all systems
## (none, retro, scanlines)
global.shaderset=retro

Now the games in those two emulators launch (I can hear the sound and music of the game) but there is no image. If I remove the specific shaders configuration for the emulator the image comes back