centos 6 安装 postgresql 时报错 是什么原因

# yum install https://yum.postgresql.org/repopackages.php
Loaded plugins: fastestmirror, security
Repository pgdg95 is listed more than once in the configuration
Repository pgdg95-source is listed more than once in the configuration
Loading mirror speeds from cached hostfile
* base: mirrors.163.com
* extras: mirrors.cn99.com
* updates: mirrors.163.com
http://yum.postgresql.org/9.1/redhat/rhel-6-x86_64/repodata/848431430287d618aa1991ec8d95a5263bfe9f5fcf8dbd9c6fedd79616f85380-primary.sqlite.bz2: [Errno 14] problem making ssl connection
Trying other mirror.
Error: failure: repodata/848431430287d618aa1991ec8d95a5263bfe9f5fcf8dbd9c6fedd79616f85380-primary.sqlite.bz2 from pgdg91: [Errno 256] No more mirrors to try.