Cargo network issue when work with Docker

Change cargo registry config

Start the capsule docker container use below command：

DOCKER_IMAGE=jjy0/ckb-capsule-recipe-rust:2020-9-28
docker run --rm -it \
    -eUID=`id -u` -eGID=`id -g` -eUSER=`id -un`\
    -v capsule-cache:/root/.cargo \
    -v `pwd`:/code \
    -w/code ${DOCKER_IMAGE} bash

Update ~/.cargo/config in docker with follow content (for Chinese user)：

cat > ~/.cargo/config << EOF
[source.crates-io]
replace-with = 'sjtu'

# 清华大学
[source.tuna]
registry = "https://mirrors.tuna.tsinghua.edu.cn/git/crates.io-index.git"

# 中国科学技术大学
[source.ustc]
registry = "https://mirrors.ustc.edu.cn/crates.io-index"

# 上海交通大学
[source.sjtu]
registry = "https://mirrors.sjtug.sjtu.edu.cn/git/crates.io-index"

# rustcc社区
[source.rustcc]
registry = "git://crates.rustcc.cn/crates.io-index"
EOF

Since we use docker's volume mount feature, the changes will be persisted.