Nividiagpu plugin: Does not parse GPU utilisation correctly due to case sensitivity

[SnapperTT]

bumblebee-status/bumblebee_status/modules/contrib/nvidiagpu.py

Line 72 in ad00333

if key == "Gpu":

The problem:

$ nvidia-smi -q | grep -A 5 Utilization
    Utilization
        GPU                                            : 0 %
        Memory                                         : 0 %
        Encoder                                        : 0 %
        Decoder                                        : 0 %
        JPEG                                           : 0 %

The script is looking for the string "Gpu" but Nvidfia-smi outputs "GPU". This can be fixed by making all string comparisons case-insensitive