Bug#963980: bumblebee-nvidia: Bumblebee daemon reported: error: [XORG] (EE) Unable to locate/open config directory

[Vincas Dargis]

In https://wiki.debian.org/Bumblebee#Debian_10_and_older I've found this hint:

```
[ERROR]Cannot access secondary GPU - error: [XORG] (EE) No devices detected

You may have to set the BusID manually, in /etc/bumblebee/xorg.conf.nvidia. To get the BusID, run lspci | egrep 'VGA|3D' 
in a terminal. Refer to the comments in that file for further instructions.
```

So I've edited `/etc/bumblebee/xorg.conf.nvidia` and uncommented one line so it's now:

```
BusID "PCI:01:00:0"
```

And it works!

`lspci | egrep 'VGA|3D'` on my machine returns:

```
00:02.0 VGA compatible controller: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller (rev 06)
01:00.0 3D controller: NVIDIA Corporation GM107M [GeForce GTX 860M] (rev ff)
```

So some part fails to detect that only NVIDIA card..? :)