在centos 上使用docker pull 拉取不了（1.6.1）镜像了啊；
我的这台服务器上以前已经安装过1.5.5的镜像，容器运行都是正常的；
现在拉取1.6.1，总是报错，（连接不了）
[root@wpvreader-res ~]# docker pull registry.docker-cn.com/halohub/halo:1.6.1
Error response from daemon: Get https://registry.docker-cn.com/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
[root@wpvreader-res ~]# docker pull 5o6jfzpx.mirror.aliyuncs.com/halohub/halo:1.6.1
Error response from daemon: Get https://5o6jfzpx.mirror.aliyuncs.com/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
[root@wpvreader-res ~]# docker pull halohub/halo:1.6.1
Error response from daemon: Get https://registry-1.docker.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
[root@wpvreader-res ~]#
