[Fix]: fix GPG key error (open-mmlab#8215)

docker/Dockerfile

@@ -8,6 +8,10 @@ ENV TORCH_CUDA_ARCH_LIST="6.0 6.1 7.0+PTX"
 ENV TORCH_NVCC_FLAGS="-Xfatbin -compress-all"
 ENV CMAKE_PREFIX_PATH="$(dirname $(which conda))/../"
 
+# To fix GPG key error when running apt-get update
+RUN apt-key adv --fetch-keys https://developer.download.nvidia.com/compute/cuda/repos/ubuntu1804/x86_64/3bf863cc.pub
+RUN apt-key adv --fetch-keys https://developer.download.nvidia.com/compute/machine-learning/repos/ubuntu1804/x86_64/7fa2af80.pub
+
 RUN apt-get update && apt-get install -y ffmpeg libsm6 libxext6 git ninja-build libglib2.0-0 libsm6 libxrender-dev libxext6 \
     && apt-get clean \
     && rm -rf /var/lib/apt/lists/*