Excavator uses all the GPUs, regardless the GPU count in the config
I have a mixed RIG: 3x 1080 Ti, 3x 1070 Ti
I wanted to use only the 1080 Tis with NemosMiner, and the 3x 1070 Tis would always mine Equihash with the DSTM miner.

```
...
"GPUCount":  3,
...
"SelGPUCC":  "0,1,2",
"SelGPUDSTM":  "0 1 2",
...
```

But this is not possible, because when Excavator comes in, the config adds up to 19 workers, so as my 6 cards as well, not only the first 3 (1080 Tis).