Fix crash on picking game media folder on Windows due to null directory #876

Job	Run time
Build Godot (32 Bits)	53m 23s
Build Godot (32 Bits)	53m 23s
Build Godot (32 Bits)	53m 23s
Build Godot (32 Bits)	53m 23s
Build Godot (32 Bits)	53m 23s
Build Godot (32 Bits)	53m 23s
Build Godot (32 Bits)	53m 23s
Build FFmpeg (32 Bits)	28s
Build FFmpeg (32 Bits)	2m 7s
Build FFmpeg (32 Bits)	43m 18s
Build FFmpeg (32 Bits)	33s
Build FFmpeg (32 Bits)	59m 41s
Build FFmpeg (32 Bits)	47m 9s
Build FFmpeg (32 Bits)	1h 17m 43s
Build Godot (64 Bits)	53m 9s
Build Godot (64 Bits)	53m 9s
Build Godot (64 Bits)	53m 9s
Build Godot (64 Bits)	53m 9s
Build Godot (64 Bits)	53m 9s
Build Godot (64 Bits)	53m 9s
Build Godot (64 Bits)	53m 9s
Build FFmpeg (64 Bits)	30s
Build FFmpeg (64 Bits)	2m 4s
Build FFmpeg (64 Bits)	43m 34s
Build FFmpeg (64 Bits)	32s
Build FFmpeg (64 Bits)	59m 22s
Build FFmpeg (64 Bits)	47m 24s
Build FFmpeg (64 Bits)	1h 20m 46s
Build EIRTeam.FFmpeg (${{ matrix.name }})	0s
Build EIRTeam.FFmpeg (${{ matrix.name }})	0s
Build EIRTeam.FFmpeg (${{ matrix.name }})	0s
Build EIRTeam.FFmpeg (${{ matrix.name }})	1s
Build EIRTeam.FFmpeg (${{ matrix.name }})	0s
Build EIRTeam.FFmpeg (${{ matrix.name }})	0s
Build RetroHub (${{ matrix.name }})	0s
Build RetroHub (${{ matrix.name }})	0s
Build RetroHub (${{ matrix.name }})	0s
Build RetroHub (${{ matrix.name }})	1s
Build RetroHub (${{ matrix.name }})	0s
Build RetroHub (${{ matrix.name }})	0s
Build EIRTeam.FFmpeg (32 Bits)	13m 1s
Build EIRTeam.FFmpeg (64 Bits)	12m 39s
Build RetroHub (32 Bits)	1m 50s
Build RetroHub (64 Bits)	1m 25s
	20h 39m 52s

Provide feedback