cocoapods-1.8.4版本错误

错误内容：

[!] CDN: trunk Repo update failed - 7 error(s):
CDN: trunk URL couldn't be downloaded: https://raw.githubusercontent.com/CocoaPods/Specs/master/Specs/0/f/b/MJRefresh/1.3.5/MJRefresh.podspec.json, error: Failed to open TCP connection to raw.githubusercontent.com:443 (Connection refused - connect(2) for "raw.githubusercontent.com" port 443)
CDN: trunk URL couldn't be downloaded: https://raw.githubusercontent.com/CocoaPods/Specs/master/Specs/0/f/b/MJRefresh/2.4.1/MJRefresh.podspec.json, error: Failed to open TCP connection to raw.githubusercontent.com:443 (Connection refused - connect(2) for "raw.githubusercontent.com" port 443)
CDN: trunk URL couldn't be downloaded: https://raw.githubusercontent.com/CocoaPods/Specs/master/Specs/0/f/b/MJRefresh/2.4.11/MJRefresh.podspec.json, error: Failed to open TCP connection to raw.githubusercontent.com:443 (Connection refused - connect(2) for "raw.githubusercontent.com" port 443)
CDN: trunk URL couldn't be downloaded: https://raw.githubusercontent.com/CocoaPods/Specs/master/Specs/0/f/b/MJRefresh/3.0.6/MJRefresh.podspec.json, error: Failed to open TCP connection to raw.githubusercontent.com:443 (Connection refused - connect(2) for "raw.githubusercontent.com" port 443)
CDN: trunk URL couldn't be downloaded: https://raw.githubusercontent.com/CocoaPods/Specs/master/Specs/0/f/b/MJRefresh/3.1.0/MJRefresh.podspec.json, error: Failed to open TCP connection to raw.githubusercontent.com:443 (Connection refused - connect(2) for "raw.githubusercontent.com" port 443)
CDN: trunk URL couldn't be downloaded: https://raw.githubusercontent.com/CocoaPods/Specs/master/Specs/0/f/b/MJRefresh/3.1.12/MJRefresh.podspec.json, error: Failed to open TCP connection to raw.githubusercontent.com:443 (Connection refused - connect(2) for "raw.githubusercontent.com" port 443)
CDN: trunk URL couldn't be downloaded: https://raw.githubusercontent.com/CocoaPods/Specs/master/Specs/0/f/b/MJRefresh/3.1.15.3/MJRefresh.podspec.json, error: Failed to open TCP connection to raw.githubusercontent.com:443 (Connection refused - connect(2) for "raw.githubusercontent.com" port 443)

解决办法：
终端运行：pod repo remove trunk