Add ARG HTTP_PROXY in Dockerfile to support HTTP proxy during image building.

Former-commit-id: c46af4c45f96f1942dfaf77bdbdbe5d0fe85a387

docker/docker-cuda/Dockerfile

@@ -22,6 +22,7 @@ ARG HTTP_PROXY=
 # Set the working directory
 WORKDIR /app
 
+# Set http proxy
 RUN if [ -n "$HTTP_PROXY" ]; then \  
         echo "Configuring proxy..."; \  
         export http_proxy=$HTTP_PROXY; \  
@@ -82,6 +83,7 @@ RUN pip uninstall -y transformer-engine flash-attn && \
     fi
 
 
+# Unset http proxy
 RUN if [ -n "$HTTP_PROXY" ]; then \
         unset http_proxy; \
         unset https_proxy; \